12-18-2025 CC Item 6A (Ritz) Public Comments — Rancho Mirage City Council, December 18, 2025 (part 3 of 4)

Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter Date: 1/12/2021 2:30 PM
tblVehicleTrips ST_TR
tblVehicleTrips
tblVehicleTrips
tblVehicleTrips
tblVehicleTrips
tblVehicleTrips
tblVehicleTrips
tblVehicleTrips
tblVehicleTrips
tblVehicleTrips
tblVehicleTrips
tblVehicleTrips
tblVehicleTrips
tblVehicleTrips
tblVehicleTrips
tblVehicleTrips
tblVehicleTrips
tblWoodstoves
tblWoodstoves
tblWoodstoves
tblWoodstoves
tblWoodstoves
tblWoodstoves
tblWoodstoves
tblWoodstoves
4 Y
•
•

•

•
•

•
•
Y
•

•

•
•

•
•
•
Y
•
•

•
•
Y
•

•

•
•

•
•
Y
•
•

•
•
Y
•
•
ST_TR
ST_TR
SU_TR
SU_TR
SU_TR
SU_TR
SU_TR
SU_TR
SU_TR
WD_TR
WD_TR
WD_TR
WD_TR
WD_TR
WD_TR
WD_TR
NumberCatalytic
NumberCatalytic
NumberNoncatalytic
NumberNoncatalytic
WoodstoveDayYear
WoodstoveDayYear
WoodstoveWoodMass
WoodstoveWoodMass
4 •
•
•
•
•
•
•
Y
•
•

8.19 94.36

49.97 6.07

5.86 1.05
131.84

5.95 72.16

25.24 6.59

6.65 11.03
127.15

8.17 89.95

42.70 1.25

48.75 1.25

48.75 25.00

25.00 999.60
i
4 i
4 i
4 4
4 1�
T
4 i
4 i
4 i
4 4 1i
1e
i
4 f
4 1�
T
i
4 i
f
i
i
t
4i
1�
i
4 4

3.75 63.99

10.74 6.16

4.18 0.69

78.27 3.20

57.65 6.39

5.83 4.13

6.41 65.80

3.84 62.64

9.43 0.00

0.00 0.00

0.00 0.00
999.60 0.00

2.0 Emissions Summary

CalEEMod Version: CalEEMod.2016.3.2 Page 4 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

2.1 Overall Construction (Maximum Daily Emission)
Unmitigated Construction
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5 Bio- CO2
Total
NBio- CO2
Total CO2
CH4
N2O
CO2e
Year
lb/day
lb/day
2021 •• 4.2621
2022 •• 4.7966 •
2023 •• 4.3939

46.4460
MI
MI

38.8851

25.8648
2024 •• 237.0656 • 9.5503
MI

31.4068

39.6338

37.5031

14.9372

0.0635

0.1195

0.1162

0.0238

18.2032

8.8255

7.0088

1.2171

2.0456

1.6361

0.7598

0.4694

20.2488

10.4616

7.7685

1.2875

9.9670 • 1.8820

3.6369 • 1.5052

1.8799 • 0.7142

0.3229 • 0.4319

11.8490

0.0000

5.1421 0.0000

2.5940 } 0.0000

0.4621 } 0.0000
6,154.337 • 6,154.337 • 1.9472 • 0.0000 • 6,203.018
7 7 6
•
12,035.34 • 12,035.34 • 1.9482 • 0.0000 . 12,060.60
40 40 13
11,710.40 • 11,710.40 • 0.9617 • 0.0000 • 11,734.44
80 80 97
•
2,307.051 • 2,307.051 • 0.7164 • 0.0000 • 2,324.962
7 7 7
Maximum I237.0656

46.4460

39.6338

0.1195

18.2032

2.0456

20.2488

9.9670

1.8820

11.8490

0.0000
12,035.34
40 12,035.34
40 1.9482

0.0000
12,060.60
13 2023 •• 4.3939
MI
MI
CalEEMod Version: CalEEMod.2016.3.2 Page 5 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

2.1 Overall Construction (Maximum Daily Emission)
Mitigated Construction
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5 Bio- CO2
Total
NBio- CO2
Total CO2
CH4
N2O
CO2e
Year
lb/day
lb/day
2021 •• 4.2621
2022 •• 4.7966
•
•
M.
•

46.4460

38.8851

25.8648
2024 •• 237.0656 • 9.5503
MI

31.4068

39.6338

37.5031

14.9372

0.0635

0.1195

0.1162

0.0238

18.2032

8.8255

7.0088

1.2171

2.0456

1.6361

0.7598

0.4694

20.2488

10.4616

7.7685

1.2875

9.9670

3.6369

1.8799

0.3229

1.8820

1.5052

0.7142

0.4319

11.8490

0.0000

5.1421 0.0000

2.5940 } 0.0000

0.4621 } 0.0000
6,154.337 • 6,154.337 • 1.9472 • 0.0000 • 6,203.018
7 7 6
•
12,035.34 • 12,035.34 • • 1.9482 • 0.0000 . 12,060.60
40 40 13
11,710.40 • 11,710.40 • • 0.9617 • 0.0000 • 11,734.44
80 80 97
•
2,307.051 • 2,307.051 • • 0.7164 • 0.0000 • 2,324.962
7 7 7
Maximum I237.0656

46.4460

39.6338

0.1195

18.2032

2.0456

20.2488

9.9670

1.8820

11.8490

0.0000
12,035.34
40 12,035.34
40 1.9482

0.0000
12,060.60
13 ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio-CO2
Total CO2
CH4
N20
CO2e
Percent
Reduction

0.00 0.00

CalEEMod Version: CalEEMod.2016.3.2 Page 6 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

2.2 Overall Operational
Unmitigated Operational
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Area
• 30.5020 : 15.0496 : 88.4430 : 0.0944
Energy 0.7660 • 6.7462 . 4.2573 • 0.0418
MI
Mobile . 9.5233 ' 45.9914 ' 110.0422
MI
MI

1.5974 : 1.5974

0.5292 • 0.5292

1.5974

0.5292

1.5974

0.5292

0.4681 : 45.9592 : 0.3373 : 46.2965 : 12.2950 : 0.3132 : 12.6083

0.0000
18,148.59 ' 18,148.59
50 50

0.4874

0.3300
18,259.11
92 8,355.983 ' 8,355.983 ' 0.1602 ' 0.1532 • 8,405.638
2 2 7
47,917.80 . 47,917.80 ' 2.1953 . T 47,972.68
05 05 39
Total
II 40.7912
Mitigated Operational

67.7872
202.7424

0.6043

45.9592

2.4640

48.4231

12.2950

2.4399

14.7349

0.0000
74,422.37
87 74,422.37
87 2.8429

0.4832
74,637.44
17 ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Area ••
Si
Energy
•,
Mobile

30.5020 •
7 . 0.7660 •
7 . 9.5233 •

15.0496
1 6.7462
1 45.9914
' 88.4430 •
7 ' 4.2573 •
7 ' 110.0422 •

0.0944
1 0.0418
7 0.4681
7 • •
1 • 45.9592 •

1.5974
7 0.5292 •
7 0.3373 •

1.5974

0.5292
1 46.2965
7 ' .
7 ' 12.2950 •

1.5974

0.5292

0.3132

1.5974
T 't
. 0.5292
T *
• 12.6083
} 0.0000
8 7
s
;
18,148.59
50 1
8,355.983
1 . 47,917.80
05 18,148.59
50 7
' 8,355.983 •
7 ' 47,917.80 •
, 05 ,

0.4874
7 0.1602
1 2.1953

0.3300 18,259.11
92 T
' 0.1532 • 8,405.638
T
' • 47,972.68
, 39
Total II

40.7912

67.7872
202.7424

0.6043

45.9592

2.4640

48.4231

12.2950

2.4399

14.7349

0.0000
74,422.37
87 74,422.37
87 2.8429

0.4832
74,637.44
17 CaIEEMod Version: CaIEEMod.2016.3.2

Page 7 of 35 ends

0.00 0.00

3.0 Construction Detail
Construction Phase
Phase
Number
Phase Name
Phase Type
I Start Date End Date I Num Days Num Days Phase Description Week
:9/1/2021
1 2
3 Demolition
:Site Preparation
:Grading
Demolition
:Site Preparation
:Grading
10/12/2021
10/13/2021 :11/9/2021
4 5: 30:
i 4 t
5: 20.
:11/10/2021 :1/11/2022 5
4 4 :Building Construction :Building Construction 1/12/2022 :12/12/2023 : 5 5 • Paving • Paving :12/13/2023 :1/30/2024 : 5: 35:
r r I-
6 :Architectural Coating :A- rchitectural Coating 1- /31/2024 '3/19/2024 5: 35:
45:
500:

Acres of Grading (Site Preparation Phase): 0
Acres of Grading (Grading Phase): 112.5
Acres of Paving: 0
Residential Indoor: 2,025,000; Residential Outdoor: 675,000; Non -Residential Indoor: 326,400; Non -Residential Outdoor: 108,800; Striped Parking Area: 0 (Architectural Coating — sqft)
OffRoad Equipment

CalEEMod Version: CalEEMod.2016.3.2

Page 8 of 35 ends

Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter Date: 1/12/2021 2:30 PM
Phase Name
Offroad Equipment Type
Amount
Usage Hours
Horse Power
Load Factor
Demolition :Concrete/Industrial Saws : 1 8.00:

I a I.

Demolition :Excavators 3 8.00'
: I , F
Demolition :Rubber Tired Dozers 2 8.00
: F
Site Preparation :Rubber Tired Dozers 3 8.00' 247
: I , F
Site Preparation •Tractors/Loaders/Backhoes : 4 8.00
: I a
Grading
81:
158:
247:

Grading
:Excavators
: Graders
Grading :Rubber Tired Dozers
Grading
: Scrapers
Grading :Tractors/Loaders/Backhoes
Building Construction
Building Construction
Building Construction
Building Construction
Building Construction
Paving
Paving
Paving
: Cranes
:Forklifts
: Generator Sets
2 2
2 a
1 3�
1-I
a
:Tractors/Loaders/Backhoes : 3
Welders
• Pavers : 2
:Paving Equipment 2
1�
:Rollers
Architectural Coating :Air Compressors
a

0.73 0.38

0.40 0.40
97: 0.37

8.00' 158: 0.38

8.00' 187: 0.41

8.00' 247: 0.40

8.00' 367;

8.00 7.00

8.00'

7.00'

8.00'

8.00 a F
2 8.00
1:
4-

6.00 0.48
97: 0.37
231: 0.29
89: 0.20
84: 0.74
97: 0.37
46: 0.45
130: 0.42
132'

0.36 80: 0.38
78: 0.48
Trips and VMT

CaIEEMod Version: CaIEEMod.2016.3.2

Page 9 of 35 ends

Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter Date: 1/12/2021 2:30 PM
Phase Name
Offroad Equipment
Count
Worker Trip
Number
Vendor Trip
Number
Hauling Trip
Number
Worker Trip
Length
Vendor Trip
Length
Hauling Trip
Length
Worker Vehicle
Class
Vendor
Vehicle Class
Hauling
Vehicle Class
Demolition 6: 15.00' 0.00 i 458.00' 10.00: 6.90' 20.00' LD_Mix i HDT_Mix 'HHDT �- : -I 4 I
Site Preparation 7' 18.00' 0.00 i 0.00' 10.00: 6.90: 20.00: LD_Mix ' HDT_Mix ! HHDT Grading 8' 20.00' 0.001 0.00'- - 10.00: 6.90' 20.00: LD_Mix :HDT_Mix 'HHDT ' r
Building Construction : 91- 801.00' 143.001 0.00' - 10.00: 6.90: 20.00! LD_Mix : HDT_Mix : HHDT ' I I I. ----------I I
Paving • 6' 15.00' 0.00: 0.00'- 10.00: 6.90: 20.00: LD_Mix : HDT_Mix : HHDT • + + I- a- +- 4
Architectural Coating
1: 160.00' 0.00' 0.00' 10.00' 6.90' 20.00' LD_Mix ' HDT_Mix ' HHDT

3.1 Mitigation Measures Construction

3.2 Demolition - 2021
Unmitigated Construction On -Site
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Fugitive Dust
•
' 3.3074 : 0.0000 ' 3.3074 ' 0.5008 : 0.0000 ' 0.5008
' 0.0000 ' ' 0.0000
.

T l 7 1 l l l 7 l *
l 1 ,
Off -Road
. 3.1651 ' 31.4407 . 21.5650 ' 0.0388 . ' 1.5513 . 1.5513 . . 1.4411 • 1.4411 i • 3,747.944 . 3,747.944 . 1.0549 . ? 3,774.317
9 9
4 Total

3.1651

31.4407

21.5650

0.0388

3.3074

1.5513

4.8588

0.5008

1.4411

1.9419
3,747.944
3,747.944

1.0549
3,774.317
II
9 9
4 CalEEMod Version: CalEEMod.2016.3.2 Page 10 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

3.2 Demolition - 2021
Unmitigated Construction Off -Site
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Hauling 7,

0.1304 • 4.1454 ' 1.0182 ' 0.0117 ' 0.2669 ' 0.0128 • 0.2797 • 0.0732 ' 0.0122 • 0.0854 } 1,269.855 • 1,269.855 • 0.0908 • ' 1,272.125
5 5 2
•:
r
Vendor

0.0000 : 0.0000 : 0.0000 : 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 }

0.0000 , 0.0000 , 0.0000 , , 0.0000
r
Worker •'

0.0532 • 0.0346 ' 0.3963 ' 1.1100e- ' 0.1141 • 9.5000e- • 0.1151 ' 0.0303 • 8.8000e- • 0.0311 i 110.4707 ' 110.4707 • 3.3300e- ' , 110.5539
003
004
004
003
Total

0.1835

4.1800

1.4144

0.0128

0.3810

0.0137

0.3948

0.1034

0.0131

0.1165
1,380.326
1,380.326

0.0941
1,382.679
II
2 2
1 Mitigated Construction On -Site
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Fugitive Dust : 3.3074 : 0.0000 : 3.3074 : 0.5008 : 0.0000 : 0.5008 • : 0.0000 : : 0.0000 I
I. 7 7 4 7 7 7 T 1 7 4 7 T
Off -Road •'

3.1651 •

31.4407 •

21.5650 •

0.0388 •
, 1.5513 •

1.5513 •
, 1.4411 •

1.4411 ; 0.0000 •
3,747.944
• 3,747.944 •

1.0549 •
' 3,774.317
Total

3.1651

31.4407

21.5650

0.0388

3.3074

1.5513

4.8588

0.5008

1.4411

1.9419

0.0000
3,747.944
3,747.944

1.0549
3,774.317
9 9
4 CaIEEMod Version: CaIEEMod.2016.3.2 Page 11 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

3.2 Demolition - 2021
Mitigated Construction Off -Site
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Hauling 7,

0.1304 • 4.1454 • 1.0182 : 0.0117 : 0.2669 : 0.0128 • 0.2797 • 0.0732 : 0.0122 • 0.0854 } 1,269.855 • 1,269.855 • 0.0908 • : 1,272.125
5 5 2
r
Vendor
, 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 }

0.0000 , 0.0000 , 0.0000 , , 0.0000
7,
r
Worker

0.0532 • 0.0346 • 0.3963 , 1.1100e- , 0.1141 , 9.5000e- • 0.1151 , 0.0303 , 8.8000e- • 0.0311 i 110.4707 , 110.4707 • 3.3300e- , , 110.5539
003
004
004
003
Total

0.1835

4.1800

1.4144

0.0128

0.3810

0.0137

0.3948

0.1034

0.0131

0.1165
1,380.326
1,380.326

0.0941
1,382.679
II
2 2
1 3.3 Site Preparation - 2021
Unmitigated Construction On -Site
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Fugitive Dust , 18.0663 , 0.0000 , 18.0663 , 9.9307 , 0.0000 , 9.9307 • : 0.0000 : ' 0.0000
I. 7 7 4 7 1 4 7 4 T 1
d
7 4 7 T
Off -Road •, 3.8882 • 40.4971 • 21.1543 • 0.0380 • • 2.0445 • 2.0445 • • 1.8809 • 1.8809 ; • 3,685.656 • 3,685.656 • 1.1920 • ' 3,715.457
3 Total

3.8882

40.4971

21.1543

0.0380

18.0663

2.0445

20.1107

9.9307

1.8809

11.8116
3,685.656
3,685.656

1.1920
3,715.457
9 9
3 CaIEEMod Version: CaIEEMod.2016.3.2 Page 12 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

3.3 Site Preparation - 2021
Unmitigated Construction Off -Site
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Hauling 7,

0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 , 0.0000 }

0.0000 : 0.0000 : 0.0000 : : 0.0000
r
Vendor
, 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 }

0.0000 , 0.0000 , 0.0000 , , 0.0000
7,
,-
Worker

0.0638 • 0.0415 , 0.4755 , 1.3300e- , 0.1369 , 1.1400e- • 0.1381 , 0.0363 , 1.0500e- • 0.0374 } 132.5649 , 132.5649 • 3.9900e- .
003
003
003
003
Total

0.0638

0.0415

0.4755

1.3300e-

0.1369

1.1400e-

0.1381

0.0363

1.0500e-

0.0374
132.5649
132.5649

3.9900e-
132.6646
II
003
003
003
003
Mitigated Construction On -Site
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Fugitive Dust : 18.0663 : 0.0000 : 18.0663 : 9.9307 : 0.0000 : 9.9307 • : 0.0000 : : 0.0000 ., 7 7 1 7 1 7 1 -r 1 7 -1 7 T
Off -Road •, 3.8882 • 40.4971 • 21.1543 • 0.0380 • • 2.0445 • 2.0445 • • 1.8809 • 1.8809 ; 0.0000 • 3,685.656 • 3,685.656 • 1.1920 • • 3,715.457 3 Total

3.8882

40.4971

21.1543

0.0380

18.0663

2.0445

20.1107

9.9307

1.8809

11.8116

0.0000
3,685.656
3,685.656

1.1920
3,715.457
9 9
3 CalEEMod Version: CalEEMod.2016.3.2 Page 13 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

3.3 Site Preparation - 2021
Mitigated Construction Off -Site
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Hauling 7,

0.0000 : 0.0000 : 0.0000 • 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 ;

0.0000 : 0.0000 : 0.0000 : : 0.0000
7•
T
Vendor

0.0000 • 0.0000 • 0.0000 • 0.0000 • 0.0000 • 0.0000 • 0.0000 • 0.0000 • 0.0000 • 0.0000 }

0.0000 • 0.0000 • 0.0000 • , 0.0000
7•
T
Worker

0.0638 • 0.0415 • 0.4755 • 1.3300e- • 0.1369 • 1.1400e- • 0.1381 • 0.0363 • 1.0500e- • 0.0374 ; 132.5649 • 132.5649 • 3.9900e- • T 132.6646
003
003
003
003
Total

0.0638

0.0415

0.4755

1.3300e-

0.1369

1.1400e-

0.1381

0.0363

1.0500e-

0.0374
132.5649
132.5649

3.9900e-
132.6646
II
003
003
003
003

3.4 Grading - 2021
Unmitigated Construction On -Site
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Fugitive Dust : 8.6733 : 0.0000 : 8.6733 : 3.5965 : 0.0000 : 3.5965 ; : 0.0000 : : 0.0000 d
Cl 7 7 1 7 T 1 7 1 7 T
Off -Road •• 4.1912 • 46.3998 • 30.8785 • 0.0620 • • 1.9853 • 1.9853 • • 1.8265 • 1.8265 ; • 6,007.043 • 6,007.043 • 1.9428 • • 6,055.613 •
•
• •
• •
•
• •
Z
4 • 4 •
•
4 Total

4.1912

46.3998

30.8785

0.0620

8.6733

1.9853

10.6587

3.5965

1.8265

5.4230
6,007.043
6,007.043

1.9428
6,055.613
4 4
4 CalEEMod Version: CalEEMod.2016.3.2 Page 14 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

3.4 Grading - 2021
Unmitigated Construction Off -Site
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Hauling 7,

0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 ;

0.0000 : 0.0000 : 0.0000 : : 0.0000
7,
r
Vendor

0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 }

0.0000 , 0.0000 , 0.0000 , , 0.0000
7,
r
Worker

0.0709 • 0.0462 , 0.5284 , 1.4800e- , 0.1521 , 1.2700e- • 0.1534 , 0.0404 , 1.1700e- • 0.0415 } 147.2943 , 147.2943 • 4.4300e- , , 147.4051
003
003
003
003
Total

0.0709

0.0462

0.5284

1.4800e-

0.1521

1.2700e-

0.1534

0.0404

1.1700e-

0.0415
147.2943
147.2943

4.4300e-
147.4051
II
003
003
003
003
Mitigated Construction On -Site
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Fugitive Dust : 8.6733 : 0.0000 : 8.6733 : 3.5965 : 0.0000 : 3.5965 ; : 0.0000 : : 0.0000 d
.. 7 7 1 7 T 1 7 1 7 T
Off -Road •,

4.1912 •

46.3998 •

30.8785 •

0.0620 •
, 1.9853 •

1.9853 •
, 1.8265 •

1.8265 ; 0.0000 •
6,007.043
• 6,007.043 •

1.9428 •
, 6,055.613
Total

4.1912

46.3998

30.8785

0.0620

8.6733

1.9853

10.6587

3.5965

1.8265

5.4230

0.0000
6,007.043
6,007.043

1.9428
6,055.613
4 4
4 CalEEMod Version: CalEEMod.2016.3.2 Page 15 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

3.4 Grading - 2021
Mitigated Construction Off -Site
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Hauling
• 0.0000 : 0.0000 : 0.0000 • 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 ;

0.0000 : 0.0000 : 0.0000 : : 0.0000
••
r
Vendor

0.0000 • 0.0000 • 0.0000 • 0.0000 • 0.0000 • 0.0000 • 0.0000 • 0.0000 • 0.0000 • 0.0000 }

0.0000 • 0.0000 • 0.0000 • ? 0.0000
••
r
Worker

0.0709 • 0.0462 • 0.5284 • 1.4800e- • 0.1521 • 1.2700e- • 0.1534 • 0.0404 • 1.1700e- • 0.0415 } 147.2943 • 147.2943 • 4.4300e- • ? 147.4051
003
003
003
003
Total

0.0709

0.0462

0.5284

1.4800e-

0.1521

1.2700e-

0.1534

0.0404

1.1700e-

0.0415
147.2943
147.2943

4.4300e-
147.4051
II
003
003
003
003

3.4 Grading - 2022
Unmitigated Construction On -Site
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Fugitive Dust : 8.6733 : 0.0000 : 8.6733 : 3.5965 : 0.0000 : 3.5965 ; : 0.0000 : : 0.0000 d
Cl 7 7 1 7 T 1 7 1 7 T
Off -Road •• 3.6248 • 38.8435 • 29.0415 • 0.0621 • • 1.6349 • 1.6349 • • 1.5041 • 1.5041 • • 6,011.410 • 6,011.410 • 1.9442 • • 6,060.015 •
•
• •
• •
•
• •
Z
5 • 5 •
•
8 Total

3.6248

38.8435

29.0415

0.0621

8.6733

1.6349

10.3082

3.5965

1.5041

5.1006
6,011.410
6,011.410

1.9442
6,060.015
5 5
8 CalEEMod Version: CalEEMod.2016.3.2 Page 16 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

3.4 Grading - 2022
Unmitigated Construction Off -Site
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Hauling 7,

0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 ;

0.0000 : 0.0000 : 0.0000 : : 0.0000
•,
r
Vendor

0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 }

0.0000 , 0.0000 , 0.0000 , , 0.0000
•,
r
Worker

0.0665 • 0.0416 , 0.4861 , 1.4300e- , 0.1521 , 1.2300e- • 0.1534 , 0.0404 , 1.1300e- • 0.0415 } 142.1207 ' 142.1207 • 4.0000e- , , 142.2207
003
003
003
003
Total

0.0665

0.0416

0.4861

1.4300e-

0.1521

1.2300e-

0.1534

0.0404

1.1300e-

0.0415
142.1207
142.1207

4.0000e-
142.2207
II
003
003
003
003
Mitigated Construction On -Site
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Fugitive Dust : 8.6733 : 0.0000 : 8.6733 : 3.5965 : 0.0000 : 3.5965 ; : 0.0000 : : 0.0000 d
C. 7 7 1 7 T 1 7 1 7 T
Off -Road •, 3.6248 • 38.8435 • 29.0415 • 0.0621 • , 1.6349 • 1.6349 • , 1.5041 • 1.5041 ; 0.0000 • 6,011.410 • 6,011.410 • 1.9442 • , 6,060.015 Z
5 : 5 ,
8 Total

3.6248

38.8435

29.0415

0.0621

8.6733

1.6349

10.3082

3.5965

1.5041

5.1006

0.0000
6,011.410
6,011.410

1.9442
6,060.015
5 5
8 CaIEEMod Version: CaIEEMod.2016.3.2 Page 17 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

3.4 Grading - 2022
Mitigated Construction Off -Site
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Hauling
, 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 }

0.0000 : 0.0000 : 0.0000 : : 0.0000
r
Vendor
, 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 }

0.0000 , 0.0000 , 0.0000 , , 0.0000
.,
r
Worker

0.0665 • 0.0416 , 0.4861 , 1.4300e- , 0.1521 , 1.2300e- • 0.1534 , 0.0404 , 1.1300e- • 0.0415 } 142.1207 , 142.1207 • 4.0000e- , , 142.2207
003
003
003
003
Total

0.0665

0.0416

0.4861

1.4300e-

0.1521

1.2300e-

0.1534

0.0404

1.1300e-

0.0415
142.1207
142.1207

4.0000e-
142.2207
II
003
003
003
003

3.5 Building Construction - 2022
Unmitigated Construction On -Site
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Off -Road
, 1.7062 •

15.6156 •

16.3634

0.0269 •

0.8090 •

0.7612 •

0.7612
•
2,554.333
. 2,554.333 •
6 0.6120 •
2,569.632
2 Total

1.7062

15.6156

16.3634

0.0269

0.8090

0.7612

2,554.333
6 2,554.333
6 0.6120
2,569.632
2 CalEEMod Version: CalEEMod.2016.3.2 Page 18 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

3.5 Building Construction - 2022
Unmitigated Construction Off -Site
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Hauling
, 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 i

0.0000 : 0.0000 : 0.0000 : : 0.0000
.,
r
Vendor

0.4284 • 13.1673 , 3.8005 • 0.0354 • 0.9155 , 0.0256 • 0.9412 • 0.2636 , 0.0245 , 0.2881 } 3,789.075 , 3,789.075 • 0.2381 • ? 3,795.028
0 : 0 3
•,
r
Worker

2.6620 • 1.6677 , 19.4699 , 0.0571 , 6.0932 • 0.0493 • 6.1425 , 1.6163 • 0.0454 • 1.6617 i 5,691.935 , 5,691.935 • 0.1602 • T 5,695.940
4 4
8 Total

3.0904

14.8350

23.2704

0.0926

7.0087

0.0749

7.0836

1.8799

0.0699

1.9498
9,481.010
9,481.010

0.3984
9,490.969
II
4 4
1 Mitigated Construction On -Site
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Off -Road
, 1.7062 •

15.6156 •

16.3634
I 0.0269 •
I 0.8090 •

0.8090 •
I

0.7612 •

0.7612

0.0000 •
2,554.333
. 2,554.333 •
6 0.6120 •
12,569.632
2 Total

1.7062

15.6156

16.3634

0.0269

0.8090

0.7612

0.0000
2,554.333
6 2,554.333
6 0.6120
2,569.632
2 CaIEEMod Version: CaIEEMod.2016.3.2 Page 19 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

3.5 Building Construction - 2022
Mitigated Construction Off -Site
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Hauling
, 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 i

0.0000 : 0.0000 : 0.0000 : : 0.0000
.,
r
Vendor

0.4284 • 13.1673 , 3.8005 • 0.0354 • 0.9155 , 0.0256 • 0.9412 • 0.2636 , 0.0245 , 0.2881 } 3,789.075 , 3,789.075 • 0.2381 • ? 3,795.028
0 : 0 3
.,
r
Worker

2.6620 • 1.6677 , 19.4699 , 0.0571 , 6.0932 , 0.0493 • 6.1425 , 1.6163 , 0.0454 • 1.6617 i 5,691.935 , 5,691.935 • 0.1602 • T 5,695.940
4 4
8 Total

3.0904

14.8350

23.2704

0.0926

7.0087

0.0749

7.0836

1.8799

0.0699

1.9498
9,481.010
9,481.010

0.3984
9,490.969
II
4 4
1 3.5 Building Construction - 2023
Unmitigated Construction On -Site
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Off -Road
• 1.5728 •

14.3849 •

16.2440
• 0.0269 •
• 0.6997 •

0.6997 •
•

0.6584 • 0.6584
- •
a
2,555.209
• 2,555.209 •

0.6079 •
• 2,570.406
Total

1.5728

14.3849

16.2440

0.0269

0.6997

0.6584

0.6584
2,555.209
9 2,555.209
9 0.6079
2,570.406
1 CalEEMod Version: CalEEMod.2016.3.2 Page 20 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

3.5 Building Construction - 2023
Unmitigated Construction Off -Site
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Hauling
, 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 , 0.0000 i

0.0000 : 0.0000 : 0.0000 : : 0.0000
r
Vendor .,

0.3183 • 9.9726 , 3.3771 , 0.0343 • 0.9156 , 0.0122 • 0.9277 • 0.2636 , 0.0116 , 0.2752 } 3,671.400 , 3,671.400 • 0.2096 •
7 7 7
•,
,-
Worker

2.5029 • 1.5073 , 17.8820 , 0.0550 , 6.0932 , 0.0479 • 6.1411 • 1.6163 , 0.0441 • 1.6604 } 5,483.797 , 5,483.797 • 0.1442 •
4 4
0 Total

2.8211

11.4799

21.2591

0.0893

7.0088

0.0601

7.0688

1.8799

0.0557

1.9356
9,155.198
9,155.198

0.3538
9,164.043
II
1 1
7 Mitigated Construction On -Site
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Off -Road . 1.5728 •

14.3849 I

16.2440
I 0.0269 •
I 0.6997 •

0.6997 • I 0.6584 • 0.6584
} 0.0000 •
8 2,555.209
9 12,555.209
: 9 :

I 0.6079 •
12,570.406
1 Total

1.5728

14.3849

16.2440

0.0269

0.6997

0.6584

0.0000
2,555.209
9 2,555.209
9 0.6079
2,570.406
1 CalEEMod Version: CalEEMod.2016.3.2 Page 21 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

3.5 Building Construction - 2023
Mitigated Construction Off -Site
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Hauling 7.

0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 I

0.0000 : 0.0000 : 0.0000 : : 0.0000

7. 7 , l , l , 7 l T *
l 1 l
Vendor

0.3183 • 9.9726 ' 3.3771 ' 0.0343 • 0.9156 . 0.0122 • 0.9277 • 0.2636 . 0.0116 , 0.2752 } 3,671.400 ' 3,671.400 • 0.2096 • T 3,676.641
7 7 7
,-
Worker •'

2.5029 • 1.5073 , 17.8820 ' 0.0550 , 6.0932 . 0.0479 • 6.1411 • 1.6163 . 0.0441 • 1.6604 } 5,483.797 , 5,483.797 • 0.1442 •
4 4
0 Total

2.8211

11.4799

21.2591

0.0893

7.0088

0.0601

7.0688

1.8799

0.0557

1.9356
9,155.198
9,155.198

0.3538
9,164.043
II
1 1
7 3.6 Paving - 2023
Unmitigated Construction On -Site
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Off -Road 7. 1.0327 • 10.1917 • 14.5842 • 0.0228 • I 0.5102 • 0.5102 • I 0.4694 • 0.4694 - • 2,207.584 . 2,207.584 • 0.7140 • ' 2,225.433 6 d
I. -. t 1 7 1 7 -, T 1 7 1 7 T
Paving : 0.0000 : : 0.0000 : 0.0000 : : 0.0000 : 0.0000 - : 0.0000 : ' 0.0000 i
Total

1.0327

10.1917

14.5842

0.0228

0.5102

0.4694

0.4694
2,207.584
2,207.584

0.7140
2,225.433
1 1
6 CalEEMod Version: CalEEMod.2016.3.2 Page 22 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

3.6 Paving - 2023
Unmitigated Construction Off -Site
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Hauling
, 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 i

0.0000 : 0.0000 : 0.0000 : : 0.0000
.
7 7 l l l l 7 l T -k l
, l
Vendor
, 0.0000 , 0.0000 , 0.0000 ' 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 }

0.0000 , 0.0000 , 0.0000 , , 0.0000
•'
T
Worker

0.0469 • 0.0282 ' 0.3349 ' 1.0300e- , 0.1141 , 9.0000e- • 0.1150 • 0.0303 , 8.3000e- • 0.0311 } 102.6928 , 102.6928 • 2.7000e- , , 102.7603
003
004
004
003
Total

0.0469

0.0282

0.3349

1.0300e-

0.1141

9.0000e-

0.1150

0.0303

8.3000e-

0.0311
102.6928
102.6928

2.7000e-
102.7603
II
003
004
004
003
Mitigated Construction On -Site
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Off -Road , 1.0327 • 10.1917 • 14.5842 • 0.0228 • I 0.5102 • 0.5102 • , 0.4694 • 0.4694 } 0.0000 • 2,207.584 , 2,207.584 , 0.7140 • ' 2,225.433 6 d
I. -. t 1 7 1 7 -, T 1
7 1 7 T
Paving , 0.0000 , , 0.0000 , 0.0000 , , 0.0000 , 0.0000 7 : 0.0000 , ' 0.0000
I
Total

1.0327

10.1917

14.5842

0.0228

0.5102

0.4694

0.0000
2,207.584
2,207.584

0.7140
2,225.433
1 1
6 CalEEMod Version: CalEEMod.2016.3.2 Page 23 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

3.6 Paving - 2023
Mitigated Construction Off -Site
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Hauling
, 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 }

0.0000 : 0.0000 : 0.0000 : : 0.0000
Vendor .,

0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 }

0.0000 , 0.0000 , 0.0000 , , 0.0000
•,
r
Worker

0.0469 • 0.0282 • 0.3349 , 1.0300e- , 0.1141 , 9.0000e- • 0.1150 , 0.0303 , 8.3000e- • 0.0311 } 102.6928 ' 102.6928 • 2.7000e- , , 102.7603
003
004
004
003
Total

0.0469

0.0282

0.3349

1.0300e-

0.1141

9.0000e-

0.1150

0.0303

8.3000e-

0.0311
102.6928
102.6928

2.7000e-
102.7603
II
003
004
004
003

3.6 Paving - 2024
Unmitigated Construction On -Site
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Off -Road , 0.9882 • 9.5246 • 14.6258 I 0.0228 • I 0.4685 • 0.4685 • I 0.4310 • 0.4310 - • 2,207.547 12,207.547 I 0.7140 • 12,225.396
3 CI 4 l l r
I
I
Paving , 0.0000 , , 0.0000 , 0.0000 , , 0.0000 , 0.0000 , 0.0000 , , 0.0000
i
Total

0.9882

9.5246

14.6258

0.0228

0.4685

0.4310

0.4310
2,207.547
2,207.547

0.7140
2,225.396
2 2
3 CalEEMod Version: CalEEMod.2016.3.2 Page 24 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

3.6 Paving - 2024
Unmitigated Construction Off -Site
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Hauling
, 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 i

0.0000 : 0.0000 : 0.0000 : : 0.0000
.,
r
Vendor

0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 }

0.0000 , 0.0000 , 0.0000 , , 0.0000
•,
r
Worker

0.0444 • 0.0257 , 0.3114 , 1.0000e- , 0.1141 , 8.8000e- • 0.1150 • 0.0303 , 8.1000e- • 0.0311 }

99.5045 ' 99.5045 • 2.4700e- ,
003
004
004
003
Total

0.0444

0.0257

0.3114

1.0000e-

0.1141

8.8000e-

0.1150

0.0303

8.1000e-

0.0311

99.5045

2.4700e-

99.5663
II
003
004
004
003
Mitigated Construction On -Site
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Off -Road . 0.9882 • 9.5246 • 14.6258 I 0.0228 • I 0.4685 • 0.4685 • I 0.4310 • 0.4310 } 0.0000 • 2,207.547 12,207.547 I 0.7140 • 12,225.396
2 2 3
II 7 t 1 7 1 7 1 T -*
7 1 7 T
Paving
, 0.0000 ,
, 0.0000 ,

0.0000 ,
, 0.0000 ,

0.0000
, 0.0000 ,
, 0.0000
Total

0.9882

9.5246

14.6258

0.0228

0.4685

0.4310

0.0000
2,207.547
2,207.547

0.7140
2,225.396
2 2
3 CaIEEMod Version: CaIEEMod.2016.3.2 Page 25 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

3.6 Paving - 2024
Mitigated Construction Off -Site
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Hauling 7,

0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 }

0.0000 : 0.0000 : 0.0000 : : 0.0000
7 7 7 l l l l 7 l T -
l 1 ,
Vendor 7,

0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 }

0.0000 , 0.0000 , 0.0000 , , 0.0000
7,
T
Worker

0.0444 • 0.0257 • 0.3114 , 1.0000e- , 0.1141 , 8.8000e- • 0.1150 , 0.0303 , 8.1000e- • 0.0311 }

99.5045 • 99.5045 • 2.4700e- ,
003
004
004
003
Total

0.0444

0.0257

0.3114

1.0000e-

0.1141

8.8000e-

0.1150

0.0303

8.1000e-

0.0311

99.5045

2.4700e-

99.5663
II
003
004
004
003

3.7 Architectural Coating - 2024
Unmitigated Construction On -Site
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Archit. Coating -: 236.4115 : : 0.0000 : 0.0000 : : 0.0000 : 0.0000 - : 0.0000 : : 0.0000 al I
f. 7 7 -, 7 1 7 7 1 T 1 7 1 7 T
Off -Road •, 0.1808 • 1.2188 • 1.8101 • 2.9700e- • • 0.0609 • 0.0609 • • 0.0609 • 0.0609 ; • 281.4481 • 281.4481 • 0.0159 • • 281.8443 003 :

Z
Total
236.5923

1.2188

1.8101

2.9700e-

0.0609

0.0609
281.4481
281.4481

0.0159
281.8443
003

CaIEEMod Version: CaIEEMod.2016.3.2 Page 26 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

3.7 Architectural Coating - 2024
Unmitigated Construction Off -Site
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Hauling 7,

0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 i

0.0000 : 0.0000 : 0.0000 : : 0.0000
7 7 7 l l l l 7 l T -k l
, l
Vendor 7,

0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 }

0.0000 , 0.0000 , 0.0000 , , 0.0000
7,
T
Worker

0.4734 • 0.2743 , 3.3220 , 0.0107 , 1.2171 , 9.4300e- • 1.2266 , 0.3229 , 8.6800e- • 0.3315 } 1,061.381 , 1,061.381 • 0.0264 ,
003
003
8 8
0 Total

0.4734

0.2743

3.3220

0.0107

1.2171

9.4300e-

1.2266

0.3229

8.6800e-

0.3315
1,061.381
1,061.381

0.0264
1,062.041
II
003
003
8 8
0 Mitigated Construction On -Site
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Archit. Coating •: 236.4115 : : 0.0000 : 0.0000 : : 0.0000 : 0.0000 - : 0.0000 : : 0.0000 •
I
I. 7 7 -, 7 1 7 -, T 1 7 1 -, T
Off -Road •, 0.1808 • 1.2188 • 1.8101 • 2.9700e- • , 0.0609 • 0.0609 • , 0.0609 • 0.0609 ; 0.0000 • 281.4481 • 281.4481 • 0.0159 • . 281.8443 003 :

Z
Total
236.5923

1.2188

1.8101

2.9700e-

0.0609

0.0000
281.4481
281.4481

0.0159
281.8443
003

CaIEEMod Version: CaIEEMod.2016.3.2 Page 27 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

3.7 Architectural Coating - 2024
Mitigated Construction Off -Site
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Hauling
, 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 : 0.0000 , 0.0000 }

0.0000 : 0.0000 : 0.0000 : : 0.0000
r
Vendor
, 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 , 0.0000 }

0.0000 , 0.0000 , 0.0000 , , 0.0000
.,
,-
Worker

0.4734 • 0.2743 , 3.3220 , 0.0107 , 1.2171 , 9.4300e- • 1.2266 , 0.3229 , 8.6800e- • 0.3315 } 1,061.381 , 1,061.381 • 0.0264 ,
003
003
8 8
0 Total

0.4734

0.2743

3.3220

0.0107

1.2171

9.4300e-

1.2266

0.3229

8.6800e-

0.3315
1,061.381
1,061.381

0.0264
1,062.041
II
003
003
8 8
0 4.0 Operational Detail - Mobile

4.1 Mitigation Measures Mobile

CaIEEMod Version: CaIEEMod.2016.3.2

Page 28 of 35 ends

Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
Mitigated • 9.5233 • 45.9914 • 110.0422 • 0.4681 • 45.9592 • 0.3373 • 46.2965 • 12.2950 • 0.3132 12.6083 } • 47,917.80 • 47,917.80 • 2.1953 • 47,972.68 05 05 39
• • d
fr f T
Unmitigated • 9.5233 • 45.9914 • 110.0422• 0.4681 • 45.9592 • 0.3373 • 46.2965 • 12.2950 • 0.3132 • 12.6083 • •47,917.80.47,917.80 • 2.1953 • . 47,972.68 in
05 05 39
3111

4.2 Trip Summary Information
Average Daily Trip Rate
Unmitigated
Mitigated
Land Use
Weekday
Saturday
Sunday
Annual VMT
Annual VMT
Apartments Low Rise
• 145.75
F
F
154.25
-F
154.00 •
506,227
506,227
Apartments Mid Rise
• 4,026.75
3,773.25
4075.50
13,660,065
13,660,065
General Office Building
288.45
F

62.55 +

31.05 •
706,812
706,812
High Turnover (Sit Down Restaurant)
• 2,368.80
2,873.52
h 2817.72 •
3,413,937
3,413,937
Hotel
192.00
I-
187.50
160.00 •
445,703
f 445,703
Quality Restaurant
501.12
i
511.92
461.20 •
707,488
707,488
Regional Shopping Center
528.08
I-
601.44
357.84 •
1,112,221
1,112,221
Total
8,050.95
8,164.43
8,057.31 1
20,552,452
20,552,452

4.3 Trip Type Information

CaIEEMod Version: CaIEEMod.2016.3.2

Page 29 of 35 ends

Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter Date: 1/12/2021 2:30 PM
Miles
Trip %
Trip Purpose %
Land Use
H -W or C -W
H -S or C -C
H -O or C -NW
H -W or C -W
H -S or C -C
H -O or C -NW
Primary
Diverted
Pass -by
Apartments Low Rise
Apartments Mid Rise
General Office Building

14.70 5.90

8.70 r r r -r
•
r r r.
z
•
r r -r
High Turnover (Sit Down 16.60 8.40 6.90 •
r •
r -r
• 16.60 8.40
r r r -r

16.60 8.40
Regional Shopping Center : 16.60 • 8.40 6.90
Hotel
Quality Restaurant

14.70 16.60

5.90 8.40

8.70 6.90

6.90 6.90

40.20 40.20

33.00 8.50

19.40 12.00

16.30 r
r
r

19.20 40.60

48.00 72.50

61.60 69.00

64.70 19.00

19.00 19.00

19.00 19.00
•
•
•
•
• • 77 • ▪ 19
✓ r
▪ 37 ▪ 20
86 86
•
•
•
•
11 11
3 3
4 43
• 58 • 38 4
✓ r r
•
•
•
•
38 54
18 35
44 11

4.4 Fleet Mix
Land Use
I LDA I LDT1 I LDT2 I MDV I LHD1 I LHD2 I MHD I HHD I OBUS I UBUS I MCY I SBUS MH • 0.543088 • 0.0442161 0.2099711 0.1163691 0.0140331
Apartments Mid Rise • • 0.543088• - 0.044216! 0.209971; 0.116369! 0.014033! General Office Building : • 0.543088• - 0.044216! 0.209971! 0.116369! 0.014033! Apartments Low Rise

0.0063321 0.021166: 0.0335771 0.0026131

0.006332! 0.021166; 0.033577! 0.002613;

0.006332; 0.021166! 0.033577; 0.002613!

0.0018171 0.0052851 0.000712

0.001817! 0.005285; 0.000712

0.001817; 0.005285! 0.000712

0.000821

0.000821
High Turnover (Sit Down : 0.543088: 0.044216: 0.209971: 0.116369: 0.014033: 0.006332. 0.021166. 0.033577. 0.002613. 0.001817. 0.005285. 0.000712. 0.000821 Restaurant) •
+ F I- E I- F I- F f t
Hotel • 0.543088• 0.0442161 0.2099711 0.1163691 0.0140331 0.0063321 0.0211661 0.0335771 0.0026131 0.0018171 0.0052851 0.000712 0.000821 4 + -I- + -1- + -I- + -I- + -I- -r
Quality Restaurant • 0.543088. - 0.0442161 0.2099711 0.1163691 0.0140331 0.0063321 0.0211661 0.0335771 0.0026131 0.0018171 0.0052851 0.000712 0.000821 4 e- -� -E -I- 4- -I- 4- -I- 4-
Regional Shopping Center : 0.543088. 0.044216. 0.209971. 0.116369. 0.014033. 0.006332. 0.021166. 0.033577. 0.002613. 0.001817. 0.005285. 0.000712.-r 0.000821

5.0 Energy Detail
Historical Energy Use: N

5.1 Mitigation Measures Energy

CaIEEMod Version: CaIEEMod.2016.3.2

Page 30 of 35 ends

Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
NaturalGas 0.7660 6.7462 4.2573 0.0418 0.5292 0.5292 0.5292 0.5292 • • 8,355.983 , 8,355.983 , 0.1602 0.1532 8,405.638 Mitigated ; ; ; ; ; ; ; ; ; 2 ; 2 ; ; 7
i i i d
m •
NaturalGas •i 0.7660 • 6.7462 • 4.2573 • 0.0418 T • 0.5292 • 0.5292 T • 0.5292 • 0.5292 • •8,355.983.8,355.983• 0.1602 • 0.1532 8,405.638 Unmitigated 2 2 7

CaIEEMod Version: CaIEEMod.2016.3.2 Page 31 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

5.2 Energy by Land Use - NaturalGas
Unmitigated
Date: 1/12/2021 2:30 PM
NaturalGa
s Use
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Land Use
kBTU/yr
lb/day
lb/day
Apartments Low •
Rise
Apartments Mid •
Rise
General Office •
Building
High Turnover (Sit '
Down Restaurant):
•
Hotel •
Quality •
Restaurant
Regional •
Shopping Center ;
1119.16 A.

A,
+,

0.0121 •
l

0.3859 •
,

0.0138 •
l

0.2455 '
,

0.0514 •
l

0.0545 '
'I 'I ,

2.7100e- •
003

0.1031
l

3.2978
n

0.1258
l

2.2314
n

0.4676
l

0.4959

0.0247
. 0.0439 •
7 . 1.4033 •
:
,
. 0.1057 •
1 . 1.8743 '
,
,
. 0.3928 •
7 . 0.4165 '

6.6000e- •
004
l

0.0211 •
,

7.5000e- •
004
l

0.0134 •
,

2.8100e- '
003
l

2.9800e- •
003

1.5000e- '
004
l
,
1 ,
l
,
. 8.3400e- .
003
l
. 0.2666 •
n
. 9.5600e- '
003
l
. 0.1696 '
n
. 0.0355 '
l
. 0.0377 '
. 1.8700e- '
003

8.3400e-
003
l

0.2666
,

9.5600e-
003
l

0.1696
,

0.0355
l

0.0377
,

1.8700e-
003
. •
l
. •
,
. •
l
. •
,
. •
l
. •
-.
. •

8.3400e- .
003

0.2666 •

9.5600e- •
003

0.1696 '

0.0355 •

0.0377 '

1.8700e- •
003

8.3400e- i
003
T *

0.2666 1
r *

9.5600e- i
003
T *

0.1696 i
I
r *

0.0355 i
T *

0.0377 i
r

1.8700e- i
003
131.6662
l
4,209.916
4 ,
150.9911
l
2,677.634
2 ,
561.1436
l
595.0298
,

29.6019
. 131.6662 •
l
. 4,209.916 '
4 n
. 150.9911 '
l
. 2,677.634 '
2 ,
. 561.1436 '
l
. 595.0298 '
n
. 29.6019 '

2.5200e- •
003
-,

0.0807 '
,

2.8900e- '
003
l

0.0513 •
,

0.0108 '
-,

0.0114 '
,

5.7000e- '
004

2.4100e- • 132.4486
003

0.0772 T 4,234.933
9 2.7700e- ? 151.8884
003

0.0491 T 2,693.546
0 0.0103 ? 564.4782

0.0109 ? 598.5658

5.4000e- ? 29.7778
004
Total
II

0.7660

6.7463

4.2573

0.0418

0.5292

0.5292
8,355.983
2 8,355.983
2 0.1602

0.1532
8,405.638
7 CaIEEMod Version: CaIEEMod.2016.3.2 Page 32 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

5.2 Energy by Land Use - NaturalGas
Mitigated
Date: 1/12/2021 2:30 PM
NaturalGa
s Use
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Land Use
kBTU/yr
lb/day
lb/day
Apartments Low • 1.11916 A.

0.0121 • 0.1031 . 0.0439 • 6.6000e- • . 8.3400e- . 8.3400e- . • 8.3400e- . 8.3400e- i 131.6662 . 131.6662 • 2.5200e- • 2.4100e- • 132.4486
Rise i;
004 003 003 003 003
003 003
+,
r f,
l l 1 l l l l l T *
l l l
Apartments Mid • 35.7843 A.

0.3859 • 3.2978 . 1.4033 • 0.0211 • . 0.2666 • 0.2666 . • 0.2666 • 0.2666 1 4,209.916 . 4,209.916 ' 0.0807 ' 0.0772 ? 4,234.933
Rise i,
:
4 4 9
A.

General Office • 1.28342 +.

0.0138 ' 0.1258 . 0.1057 • 7.5000e- • . 9.5600e- ' 9.5600e- . • 9.5600e- • 9.5600e- i 150.9911 . 150.9911 ' 2.8900e- ' 2.7700e- ? 151.8884
Building i,
004 003 003 003 003
003 003
A.

P f,
l l 1 l 1 l l l T *
l l 1
High Turnover (Sit ' 22.7599 A.

0.2455 ' 2.2314 . 1.8743 ' 0.0134 • . 0.1696 ' 0.1696 . • 0.1696 ' 0.1696 i 2,677.634 . 2,677.634 ' 0.0513 • 0.0491 T 2,693.546
Down Restaurant): i,
I
2 2 0
A.
,
Hotel • 4.76972 i.

0.0514 ' 0.4676 . 0.3928 • 2.8100e- • . 0.0355 ' 0.0355 . • 0.0355 • 0.0355 i 561.1436 . 561.1436 ' 0.0108 ' 0.0103 ? 564.4782
+,
003
+,
r f,
l l l l l l l l T *
l l l
Quality • 5.05775 A.

0.0545 ' 0.4959 . 0.4165 ' 2.9800e- • . 0.0377 ' 0.0377 . • 0.0377 ' 0.0377 i 595.0298 . 595.0298 ' 0.0114 ' 0.0109 ? 598.5658
Restaurant i,
003
A.
,
Regional • 0.251616 +.

2.7100e- ' 0.0247 • 0.0207 ' 1.5000e- • • 1.8700e- ' 1.8700e- . • 1.8700e- • 1.8700e- i

29.6019 • 29.6019 ' 5.7000e- ' 5.4000e- ? 29.7778
Shopping Center ;
i;
003
004
003
003
003
003
004
004
Total

0.7660

6.7463

4.2573

0.0418

0.5292

0.5292
8,355.983
8,355.983

0.1602

0.1532
8,405.638
II
2 2
7 6.0 Area Detail

6.1 Mitigation Measures Area

CalEEMod Version: CalEEMod.2O16.3.2

Page 33 of 35 ends

Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter Date: 1/12/2021 2:30 PM
S
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
Category
lb/day
lb/day
a
Mitigated •• 30.5020 15.0496 88.4430 0.0944 • 1.5974 • 1.5974 • • 1.5974 • 1.5974 } 0.0000 • 18,148.59 • 18,148.59 • 0.4874 • 0.3300 • 18,259.11 50 50 92
• •
•r T ;
Unmitigated •• 30.5020 • 15.0496 • 88.4430 • 0.0944 T • 1.5974 • 1.5974 T • 1.5974 • 1.5974 • 0.0000 •18,148.59'18,148.59• 0.4874 ' 0.3300 • 18,259.11 50 50 92

6.2 Area by SubCategory
Unmitigated
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
SubCategory
lb/day
lb/day
Architectural ••

2.2670 • 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000
Coating
, , , , , , , , , y
••
8 7 1 7 1 1 7 1 7 T * 1 7 4 -
Consumer ••

24.1085 • • 0.0000 • 0.0000 • • 0.0000 • 0.0000 7 • 0.0000 • • 0.0000 Products
• • • • • • • • • • •
i
Hearth
• 1.6500 • 14.1000 • 6.0000 • 0.0900 • • 1.1400 • 1.1400 • • 1.1400 • 1.1400 ; 0.0000 • 18,000.00 • 18,000.00 • 0.3450 • 0.3300 T 18,106.96 • 00 50
a
C.
7 1 7 1 1 7 1 7 T * 1 7 1 T
Landscaping
• 2.4766 • 0.9496 • 82.4430 • 4.3600e- • • 0.4574 • 0.4574 • • 0.4574 • 0.4574 7 148.5950 • 148.5950 • 0.1424 • • 152.1542 ,
003 ,
,
,
, ,
,
3 Total

30.5020

15.0496

88.4430

0.0944

1.5974

0.0000
18,148.59
18,148.59

0.4874

0.3300
18,259.11
II
50 50
92 CaIEEMod Version: CaIEEMod.2016.3.2 Page 34 of 35
Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter

6.2 Area by SubCategory
Mitigated
Date: 1/12/2021 2:30 PM
ROG
NOx
CO
SO2
Fugitive
PM10
Exhaust
PM10
PM10
Total
Fugitive
PM2.5
Exhaust
PM2.5
PM2.5
Total
Bio- CO2
NBio- CO2
Total CO2
CH4
N2O
CO2e
SubCategory
lb/day
lb/day
w
Architectural
Coating
Consumer •,
Products
Hearth
Landscaping •,
, 2.2670 •

24.1085 •
, 1.6500 ,

2.4766 •

14.1000

0.9496
i .
, 6.0000 ,
, 82.4430 •
.

0.0900 •

4.3600e- ,
003
�
,
•
'

0.0000 •

1.1400 •

0.4574 •

0.0000

0.0000
n

1.1400

0.4574
: •
, •
,
, •
, •

0.0000 ,

0.0000 ,
-r

1.1400 ,
-r

0.4574 ,

0.0000
i
i 0.0000
i
n
18,000.00
00 148.5950
: 0.0000 •
, 0.0000 ,
-,
, 18,000.00'
00 , 148.5950 ,
n

0.3450

0.1424
, • 0.0000
• 0.0000
, 0.3300 , 18,106.96
50 , , 152.1542
Total II

30.5020

15.0496

88.4430

0.0944

1.5974

0.0000
18,148.59
50 18,148.59
50 0.4874

0.3300
18,259.11
92 7.0 Water Detail

7.1 Mitigation Measures Water

8.0 Waste Detail

8.1 Mitigation Measures Waste

9.0 Operational Offroad
Equipment Type
Number
Hours/Day
Days/Year
Horse Power
Load Factor
Fuel Type

10.0 Stationary Equipment

CalEEMod Version: CalEEMod.2016.3.2

Page 35 of 35 ends

Village South Specific Plan (Proposed) - Los Angeles -South Coast County, Winter Fire Pumps and Emergency Generators
Date: 1/12/2021 2:30 PM
Equipment Type
Number
Hours/Day
Hours/Year
Horse Power
Load Factor
Fuel Type
Boilers
Equipment Type
Number
Heat Input/Day
Heat Input/Year
Boiler Rating
Fuel Type
User Defined Equipment
Equipment Type
Number

11.0 Vegetation

Attachment C
Local Hire Provision Net Change
Without Local Hire Provision
Total Construction GHG Emissions (MT CO2e)
3,623
Amortized (MT CO2e/year)
120.77
With Local Hire Provision
Total Construction GHG Emissions (MT CO2e)
3,024
Amortized (MT CO2e/year)
Decrease in Construction -related GHG Emissions
100.80
17%

EXHIBIT B

SWAPE
Technical Consultation, Data Analysis and
Litigation Support for the Environment

SOIL WATER AIR PROTECTION ENTERPRISE
2656 29th Street, Suite 201
Santa Monica, California 90405
Attn: Paul Rosenfeld, Ph.D.

Mobil: (310) 795-2335
Office: (310) 452-5555
Fax: (310) 452-5550
Email: [email protected]
Paul Rosenfeld, Ph.D.

Chemical Fate and Transport & Air Dispersion Modeling
Principal Environmental Chemist Risk Assessment & Remediation Specialist Education
Ph.D. Soil Chemistry, University of Washington, 1999. Dissertation on volatile organic compound filtration.

M.S. Environmental Science, U.C. Berkeley, 1995. Thesis on organic waste economics.

B.A. Environmental Studies, U.C. Santa Barbara, 1991. Thesis on wastewater treatment.

Professional Experience
Dr. Rosenfeld has over 25 years' experience conducting environmental investigations and risk assessments for evaluating impacts to human health, property, and ecological receptors. His expertise focuses on the fate and transport of environmental contaminants, human health risk, exposure assessment, and ecological restoration. Dr.

Rosenfeld has evaluated and modeled emissions from unconventional oil drilling operations, oil spills, landfills, boilers and incinerators, process stacks, storage tanks, confined animal feeding operations, and many other industrial and agricultural sources. His project experience ranges from monitoring and modeling of pollution sources to evaluating impacts of pollution on workers at industrial facilities and residents in surrounding communities.

Dr. Rosenfeld has investigated and designed remediation programs and risk assessments for contaminated sites containing lead, heavy metals, mold, bacteria, particulate matter, petroleum hydrocarbons, chlorinated solvents, pesticides, radioactive waste, dioxins and furans, semi- and volatile organic compounds, PCBs, PAHs, perchlorate, asbestos, per- and poly-fluoroalkyl substances (PFOA/PFOS), unusual polymers, fuel oxygenates (MTBE), among other pollutants. Dr. Rosenfeld also has experience evaluating greenhouse gas emissions from various projects and is an expert on the assessment of odors from industrial and agricultural sites, as well as the evaluation of odor nuisance impacts and technologies for abatement of odorous emissions. As a principal scientist at SWAPE, Dr. Rosenfeld directs air dispersion modeling and exposure assessments. He has served as an expert witness and testified about pollution sources causing nuisance and/or personal injury at dozens of sites and has testified as an expert witness on more than ten cases involving exposure to air contaminants from industrial sources.

Paul E. Rosenfeld, Ph.D.

Page 1 of 10 ends

Professional History:

Soil Water Air Protection Enterprise (SWAPE); 2003 to present; Principal and Founding Partner UCLA School of Public Health; 2007 to 2011; Lecturer (Assistant Researcher) UCLA School of Public Health; 2003 to 2006; Adjunct Professor UCLA Environmental Science and Engineering Program; 2002-2004; Doctoral Intern Coordinator UCLA Institute of the Environment, 2001-2002; Research Associate Komex H2O Science, 2001 to 2003; Senior Remediation Scientist National Groundwater Association, 2002-2004; Lecturer
San Diego State University, 1999-2001; Adjunct Professor Anteon Corp., San Diego, 2000-2001; Remediation Project Manager Ogden (now Amec), San Diego, 2000-2000; Remediation Project Manager Bechtel, San Diego, California, 1999 — 2000; Risk Assessor King County, Seattle, 1996 — 1999; Scientist
James River Corp., Washington, 1995-96; Scientist
Big Creek Lumber, Davenport, California, 1995; Scientist Plumas Corp., California and USFS, Tahoe 1993-1995; Scientist Peace Corps and World Wildlife Fund, St. Kitts, West Indies, 1991-1993; Scientist Publications:

Remy, L.L., Clay T., Byers, V., Rosenfeld P. E. (2019) Hospital, Health, and Community Burden After Oil Refinery Fires, Richmond, California 2007 and 2012. Environmental Health. 18:48 Simons, R.A., Seo, Y. Rosenfeld, P., (2015) Modeling the Effect of Refinery Emission On Residential Property Value. Journal of Real Estate Research. 27(3):321-342
Chen, J. A, Zapata A. R., Sutherland A. J., Molmen, D.R., Chow, B. S., Wu, L. E., Rosenfeld, P. E., Hesse, R. C., (2012) Sulfur Dioxide and Volatile Organic Compound Exposure To A Community In Texas City Texas Evaluated Using Aermod and Empirical Data. American Journal of Environmental Science, 8(6), 622-632.

Rosenfeld, P.E. & Feng, L. (2011). The Risks of Hazardous Waste. Amsterdam: Elsevier Publishing.

Cheremisinoff, N.P., & Rosenfeld, P.E. (2011). Handbook of Pollution Prevention and Cleaner Production: Best Practices in the Agrochemical Industry, Amsterdam: Elsevier Publishing.

Gonzalez, J., Feng, L., Sutherland, A., Waller, C., Sok, H., Hesse, R., Rosenfeld, P. (2010). PCBs and Dioxins/Furans in Attic Dust Collected Near Former PCB Production and Secondary Copper Facilities in Sauget, IL.

Procedia Environmental Sciences. 113-125.

Feng, L., Wu, C., Tam, L., Sutherland, A.J., Clark, J.J., Rosenfeld, P.E. (2010). Dioxin and Furan Blood Lipid and Attic Dust Concentrations in Populations Living Near Four Wood Treatment Facilities in the United States. Journal of Environmental Health. 73(6), 34-46.

Cheremisinoff, N.P., & Rosenfeld, P.E. (2010). Handbook of Pollution Prevention and Cleaner Production: Best Practices in the Wood and Paper Industries. Amsterdam: Elsevier Publishing.

Cheremisinoff, N.P., & Rosenfeld, P.E. (2009). Handbook of Pollution Prevention and Cleaner Production: Best Practices in the Petroleum Industry. Amsterdam: Elsevier Publishing.

Wu, C., Tam, L., Clark, J., Rosenfeld, P. (2009). Dioxin and furan blood lipid concentrations in populations living near four wood treatment facilities in the United States. WIT Transactions on Ecology and the Environment, Air Pollution, 123 (17), 319-327.

Paul E. Rosenfeld, Ph.D.

Page 2 of 10 ends

Tam L. K.., Wu C. D., Clark J. J. and Rosenfeld, P.E. (2008). A Statistical Analysis Of Attic Dust And Blood Lipid Concentrations Of Tetrachloro-p-Dibenzodioxin (TCDD) Toxicity Equivalency Quotients (TEQ) In Two Populations Near Wood Treatment Facilities. Organohalogen Compounds, 70, 002252-002255.

Tam L. K.., Wu C. D., Clark J. J. and Rosenfeld, P.E. (2008). Methods For Collect Samples For Assessing Dioxins And Other Environmental Contaminants In Attic Dust: A Review. Organohalogen Compounds, 70, 000527- 000530.

Hensley, A.R. A. Scott, J. J. J. Clark, Rosenfeld, P.E. (2007). Attic Dust and Human Blood Samples Collected near a Former Wood Treatment Facility. Environmental Research. 105, 194-197.

Rosenfeld, P.E., J. J. J. Clark, A. R. Hensley, M. Suffet. (2007). The Use of an Odor Wheel Classification for Evaluation of Human Health Risk Criteria for Compost Facilities. Water Science & Technology 55(5), 345-357.

Rosenfeld, P. E., M. Suffet. (2007). The Anatomy Of Odour Wheels For Odours Of Drinking Water, Wastewater, Compost And The Urban Environment. Water Science & Technology 55(5), 335-344.

Sullivan, P. J. Clark, J.J.J., Agardy, F. J., Rosenfeld, P.E. (2007). Toxic Legacy, Synthetic Toxins in the Food, Water, and Air in American Cities. Boston Massachusetts: Elsevier Publishing Rosenfeld, P.E., and Suffet I.H. (2004). Control of Compost Odor Using High Carbon Wood Ash. Water Science and Technology. 49(9),171-178.

Rosenfeld P. E., J.J. Clark, I.H. (Mel) Suffet (2004). The Value of An Odor -Quality -Wheel Classification Scheme For The Urban Environment. Water Environment Federation's Technical Exhibition and Conference (WEFTEC) 2004. New Orleans, October 2-6, 2004.

Rosenfeld, P.E., and Suffet, I.H. (2004). Understanding Odorants Associated With Compost, Biomass Facilities, and the Land Application of Biosolids. Water Science and Technology. 49(9), 193-199.

Rosenfeld, P.E., and Suffet I.H. (2004). Control of Compost Odor Using High Carbon Wood Ash, Water Science and Technology, 49( 9), 171-178.

Rosenfeld, P. E., Grey, M. A., Sellew, P. (2004). Measurement of Biosolids Odor and Odorant Emissions from Windrows, Static Pile and Biofilter. Water Environment Research. 76(4), 310-315.

Rosenfeld, P.E., Grey, M and Suffet, M. (2002). Compost Demonstration Project, Sacramento California Using High -Carbon Wood Ash to Control Odor at a Green Materials Composting Facility. Integrated Waste Management Board Public Affairs Office, Publications Clearinghouse (MS -6), Sacramento, CA Publication #442-02-008.

Rosenfeld, P.E., and C.L. Henry. (2001). Characterization of odor emissions from three different biosolids. Water Soil and Air Pollution. 127(1-4), 173-191.

Rosenfeld, P.E., and Henry C. L., (2000). Wood ash control of odor emissions from biosolids application. Journal of Environmental Quality. 29, 1662-1668.

Rosenfeld, P.E., C.L. Henry and D. Bennett. (2001). Wastewater dewatering polymer affect on biosolids odor emissions and microbial activity. Water Environment Research. 73(4), 363-367.

Rosenfeld, P.E., and C.L. Henry. (2001). Activated Carbon and Wood Ash Sorption of Wastewater, Compost, and Biosolids Odorants. Water Environment Research, 73, 388-393.

Rosenfeld, P.E., and Henry C. L., (2001). High carbon wood ash effect on biosolids microbial activity and odor.

Water Environment Research. 131(1-4), 247-262.

Paul E. Rosenfeld, Ph.D.

Page 3 of 10 ends

Chollack, T. and P. Rosenfeld. (1998). Compost Amendment Handbook For Landscaping. Prepared for and distributed by the City of Redmond, Washington State.

Rosenfeld, P. E. (1992). The Mount Liamuiga Crater Trail. Heritage Magazine of St. Kitts, 3(2).

Rosenfeld, P. E. (1993). High School Biogas Project to Prevent Deforestation On St. Kitts. Biomass Users Network, 7(1).

Rosenfeld, P. E. (1998). Characterization, Quantification, and Control of Odor Emissions From Biosolids Application To Forest Soil. Doctoral Thesis. University of Washington College of Forest Resources.

Rosenfeld, P. E. (1994). Potential Utilization of Small Diameter Trees on Sierra County Public Land. Masters thesis reprinted by the Sierra County Economic Council. Sierra County, California.

Rosenfeld, P. E. (1991). How to Build a Small Rural Anaerobic Digester & Uses Of Biogas In The First And Third World. Bachelors Thesis. University of California.

Presentations:

Rosenfeld, P.E., Sutherland, A; Hesse, R.; Zapata, A. (October 3-6, 2013). Air dispersion modeling of volatile organic emissions from multiple natural gas wells in Decatur, TX. 44th Western Regional Meeting, American Chemical Society. Lecture conducted from Santa Clara, CA.

Sok, H.L.; Waller, C.C.; Feng, L.; Gonzalez, J.; Sutherland, A.J.; Wisdom -Stack, T.; Sahai, R.K.; Hesse, R.C.; Rosenfeld, P.E. (June 20-23, 2010). Atrazine: A Persistent Pesticide in Urban Drinking Water.

Urban Environmental Pollution. Lecture conducted from Boston, MA.

Feng, L.; Gonzalez, J.; Sok, H.L.; Sutherland, A.J.; Waller, C.C.; Wisdom -Stack, T.; Sahai, R.K.; La, M.; Hesse, R.C.; Rosenfeld, P.E. (June 20-23, 2010). Bringing Environmental Justice to East St. Louis, Illinois. Urban Environmental Pollution. Lecture conducted from Boston, MA.

Rosenfeld, P.E. (April 19-23, 2009). Perfluoroctanoic Acid (PFOA) and Perfluoroactane Sulfonate (PFOS) Contamination in Drinking Water From the Use of Aqueous Film Forming Foams (AFFF) at Airports in the United States. 2009 Ground Water Summit and 2009 Ground Water Protection Council Spring Meeting, Lecture conducted from Tuscon, AZ.

Rosenfeld, P.E. (April 19-23, 2009). Cost to Filter Atrazine Contamination from Drinking Water in the United States" Contamination in Drinking Water From the Use of Aqueous Film Forming Foams (AFFF) at Airports in the United States. 2009 Ground Water Summit and 2009 Ground Water Protection Council Spring Meeting. Lecture conducted from Tuscon, AZ.

Wu, C., Tam, L., Clark, J., Rosenfeld, P. (20-22 July, 2009). Dioxin and furan blood lipid concentrations in populations living near four wood treatment facilities in the United States. Brebbia, C.A. and Popov, V., eds., Air Pollution XVII: Proceedings of the Seventeenth International Conference on Modeling, Monitoring and Management of Air Pollution. Lecture conducted from Tallinn, Estonia.

Rosenfeld, P. E. (October 15-18, 2007). Moss Point Community Exposure To Contaminants From A Releasing Facility. The 23rd Annual International Conferences on Soils Sediment and Water. Platform lecture conducted from University of Massachusetts, Amherst MA.

Rosenfeld, P. E. (October 15-18, 2007). The Repeated Trespass of Tritium -Contaminated Water Into A Surrounding Community Form Repeated Waste Spills From A Nuclear Power Plant. The 23rd Annual International Conferences on Soils Sediment and Water. Platform lecture conducted from University of Massachusetts, Amherst MA.

Paul E. Rosenfeld, Ph.D.

Page 4 of 10 ends

Rosenfeld, P. E. (October 15-18, 2007). Somerville Community Exposure To Contaminants From Wood Treatment Facility Emissions. The 23rd Annual International Conferences on Soils Sediment and Water. Lecture conducted from University of Massachusetts, Amherst MA.

Rosenfeld P. E. (March 2007). Production, Chemical Properties, Toxicology, & Treatment Case Studies of 1,2,3- Trichloropropane (TCP). The Association for Environmental Health and Sciences (AEHS) Annual Meeting. Lecture conducted from San Diego, CA.

Rosenfeld P. E. (March 2007). Blood and Attic Sampling for Dioxin/Furan, PAH, and Metal Exposure in Florala, Alabama. The AEHS Annual Meeting. Lecture conducted from San Diego, CA.

Hensley A.R., Scott, A., Rosenfeld P.E., Clark, J.J.J. (August 21 — 25, 2006). Dioxin Containing Attic Dust And Human Blood Samples Collected Near A Former Wood Treatment Facility. The 26th International Symposium on Halogenated Persistent Organic Pollutants — DIOXIN2006. Lecture conducted from Radisson SAS Scandinavia Hotel in Oslo Norway.

Hensley A.R., Scott, A., Rosenfeld P.E., Clark, J.J.J. (November 4-8, 2006). Dioxin Containing Attic Dust And Human Blood Samples Collected Near A Former Wood Treatment Facility. APHA 134 Annual Meeting & Exposition. Lecture conducted from Boston Massachusetts.

Paul Rosenfeld Ph.D. (October 24-25, 2005). Fate, Transport and Persistence of PFOA and Related Chemicals.

Mealey's C8/PFOA. Science, Risk & Litigation Conference. Lecture conducted from The Rittenhouse Hotel, Philadelphia, PA.

Paul Rosenfeld Ph.D. (September 19, 2005). Brominated Flame Retardants in Groundwater: Pathways to Human Ingestion, Toxicology and Remediation PEMA Emerging Contaminant Conference. Lecture conducted from Hilton Hotel, Irvine California.

Paul Rosenfeld Ph.D. (September 19, 2005). Fate, Transport, Toxicity, And Persistence of 1,2,3-TCP. PEMA Emerging Contaminant Conference. Lecture conducted from Hilton Hotel in Irvine, California.

Paul Rosenfeld Ph.D. (September 26-27, 2005). Fate, Transport and Persistence of PDBEs. Mealey's Groundwater Conference. Lecture conducted from Ritz Carlton Hotel, Marina Del Ray, California.

Paul Rosenfeld Ph.D. (June 7-8, 2005). Fate, Transport and Persistence of PFOA and Related Chemicals.

International Society of Environmental Forensics: Focus On Emerging Contaminants. Lecture conducted from Sheraton Oceanfront Hotel, Virginia Beach, Virginia.

Paul Rosenfeld Ph.D. (July 21-22, 2005). Fate Transport, Persistence and Toxicology of PFOA and Related Perfluorochemicals. 2005 National Groundwater Association Ground Water And Environmental Law Conference.

Lecture conducted from Wyndham Baltimore Inner Harbor, Baltimore Maryland.

Paul Rosenfeld Ph.D. (July 21-22, 2005). Brominated Flame Retardants in Groundwater: Pathways to Human Ingestion, Toxicology and Remediation. 2005 National Groundwater Association Ground Water and Environmental Law Conference. Lecture conducted from Wyndham Baltimore Inner Harbor, Baltimore Maryland.

Paul Rosenfeld, Ph.D. and James Clark Ph.D. and Rob Hesse R.G. (May 5-6, 2004). Tert-butyl Alcohol Liability and Toxicology, A National Problem and Unquantified Liability. National Groundwater Association. Environmental Law Conference. Lecture conducted from Congress Plaza Hotel, Chicago Illinois.

Paul Rosenfeld, Ph.D. (March 2004). Perchlorate Toxicology. Meeting of the American Groundwater Trust.

Lecture conducted from Phoenix Arizona.

Hagemann, M.F., Paul Rosenfeld, Ph.D. and Rob Hesse (2004). Perchlorate Contamination of the Colorado River.

Meeting of tribal representatives. Lecture conducted from Parker, AZ.

Paul E. Rosenfeld, Ph.D.

Page 5 of 10 ends

Paul Rosenfeld, Ph.D. (April 7, 2004). A National Damage Assessment Model For PCE and Dry Cleaners.

Drycleaner Symposium. California Ground Water Association. Lecture conducted from Radison Hotel, Sacramento, California.

Rosenfeld, P. E., Grey, M., (June 2003) Two stage biofilter for biosolids composting odor control. Seventh International In Situ And On Site Bioremediation Symposium Battelle Conference Orlando, FL.

Paul Rosenfeld, Ph.D. and James Clark Ph.D. (February 20-21, 2003) Understanding Historical Use, Chemical Properties, Toxicity and Regulatory Guidance of 1,4 Dioxane. National Groundwater Association. Southwest Focus Conference. Water Supply and Emerging Contaminants.. Lecture conducted from Hyatt Regency Phoenix Arizona.

Paul Rosenfeld, Ph.D. (February 6-7, 2003). Underground Storage Tank Litigation and Remediation. California CUPA Forum. Lecture conducted from Marriott Hotel, Anaheim California.

Paul Rosenfeld, Ph.D. (October 23, 2002) Underground Storage Tank Litigation and Remediation. EPA Underground Storage Tank Roundtable. Lecture conducted from Sacramento California.

Rosenfeld, P.E. and Suffet, M. (October 7- 10, 2002). Understanding Odor from Compost, Wastewater and Industrial Processes. Sixth Annual Symposium On Off Flavors in the Aquatic Environment. International Water Association. Lecture conducted from Barcelona Spain.

Rosenfeld, P.E. and Suffet, M. (October 7- 10, 2002). Using High Carbon Wood Ash to Control Compost Odor.

Sixth Annual Symposium On Off Flavors in the Aquatic Environment. International Water Association. Lecture conducted from Barcelona Spain.

Rosenfeld, P.E. and Grey, M. A. (September 22-24, 2002). Biocycle Composting For Coastal Sage Restoration.

Northwest Biosolids Management Association. Lecture conducted from Vancouver Washington..

Rosenfeld, P.E. and Grey, M. A. (November 11-14, 2002). Using High -Carbon Wood Ash to Control Odor at a Green Materials Composting Facility. Soil Science Society Annual Conference. Lecture conducted from Indianapolis, Maryland.

Rosenfeld. P.E. (September 16, 2000). Two stage biofilter for biosolids composting odor control. Water Environment Federation. Lecture conducted from Anaheim California.

Rosenfeld. P.E. (October 16, 2000). Wood ash and biofilter control of compost odor. Biofest. Lecture conducted from Ocean Shores, California.

Rosenfeld, P.E. (2000). Bioremediation Using Organic Soil Amendments. California Resource Recovery Association. Lecture conducted from Sacramento California.

Rosenfeld, P.E., C.L. Henry, R. Harrison. (1998). Oat and Grass Seed Germination and Nitrogen and Sulfur Emissions Following Biosolids Incorporation With High -Carbon Wood -Ash. Water Environment Federation 12th Annual Residuals and Biosolids Management Conference Proceedings. Lecture conducted from Bellevue Washington.

Rosenfeld, P.E., and C.L. Henry. (1999). An evaluation of ash incorporation with biosolids for odor reduction. Soil Science Society of America. Lecture conducted from Salt Lake City Utah.

Rosenfeld, P.E., C.L. Henry, R. Harrison. (1998). Comparison of Microbial Activity and Odor Emissions from Three Different Biosolids Applied to Forest Soil. Brown and Caldwell. Lecture conducted from Seattle Washington.

Rosenfeld, P.E., C.L. Henry. (1998). Characterization, Quantification, and Control of Odor Emissions from Biosolids Application To Forest Soil. Biofest. Lecture conducted from Lake Chelan, Washington.

Paul E. Rosenfeld, Ph.D.

Page 6 of 10 ends

Rosenfeld, P.E, C.L. Henry, R. Harrison. (1998). Oat and Grass Seed Germination and Nitrogen and Sulfur Emissions Following Biosolids Incorporation With High -Carbon Wood -Ash. Water Environment Federation 12th Annual Residuals and Biosolids Management Conference Proceedings. Lecture conducted from Bellevue Washington.

Rosenfeld, P.E., C.L. Henry, R. B. Harrison, and R. Dills. (1997). Comparison of Odor Emissions From Three Different Biosolids Applied to Forest Soil. Soil Science Society of America. Lecture conducted from Anaheim California.

Teaching Experience:

UCLA Department of Environmental Health (Summer 2003 through 20010) Taught Environmental Health Science 100 to students, including undergrad, medical doctors, public health professionals and nurses. Course focused on the health effects of environmental contaminants.

National Ground Water Association, Successful Remediation Technologies. Custom Course in Sante Fe, New Mexico. May 21, 2002. Focused on fate and transport of fuel contaminants associated with underground storage tanks.

National Ground Water Association; Successful Remediation Technologies Course in Chicago Illinois. April 1, 2002. Focused on fate and transport of contaminants associated with Superfund and RCRA sites.

California Integrated Waste Management Board, April and May, 2001. Alternative Landfill Caps Seminar in San Diego, Ventura, and San Francisco. Focused on both prescriptive and innovative landfill cover design.

UCLA Department of Environmental Engineering, February 5, 2002. Seminar on Successful Remediation Technologies focusing on Groundwater Remediation.

University Of Washington, Soil Science Program, Teaching Assistant for several courses including: Soil Chemistry, Organic Soil Amendments, and Soil Stability.

U.C. Berkeley, Environmental Science Program Teaching Assistant for Environmental Science 10.

Academic Grants Awarded:

California Integrated Waste Management Board. $41,000 grant awarded to UCLA Institute of the Environment.

Goal: To investigate effect of high carbon wood ash on volatile organic emissions from compost. 2001.

Synagro Technologies, Corona California: $10,000 grant awarded to San Diego State University.

Goal: investigate effect of biosolids for restoration and remediation of degraded coastal sage soils. 2000.

King County, Department of Research and Technology, Washington State. $100,000 grant awarded to University of Washington: Goal: To investigate odor emissions from biosolids application and the effect of polymers and ash on VOC emissions. 1998.

Northwest Biosolids Management Association, Washington State. $20,000 grant awarded to investigate effect of polymers and ash on VOC emissions from biosolids. 1997.

James River Corporation, Oregon: $10,000 grant was awarded to investigate the success of genetically engineered Poplar trees with resistance to round -up. 1996.

United State Forest Service, Tahoe National Forest: $15,000 grant was awarded to investigating fire ecology of the Tahoe National Forest. 1995.

Kellogg Foundation, Washington D.C. $500 grant was awarded to construct a large anaerobic digester on St. Kitts in West Indies. 1993
Paul E. Rosenfeld, Ph.D.

Page7of 10 June2019

Deposition and/or Trial Testimony:

In the United States District Court For The District of New Jersey Duarte et al, Plaintiffs, vs. United States Metals Refining Company et. al. Defendant.

Case No.: 2:17-cv-01624-ES-SCM
Rosenfeld Deposition. 6-7-2019
In the United States District Court of Southern District of Texas Galveston Division M/T Carla Maersk, Plaintiffs, vs. Conti 168., Schiffahrts-GMBH & Co. Bulker KG MS "Conti Perdido" Defendant.

Case No.: 3:15 -CV -00106 consolidated with 3:15 -CV -00237 Rosenfeld Deposition. 5-9-2019
In The Superior Court of the State of California In And For The County Of Los Angeles — Santa Monica Carole-Taddeo-Bates et al., vs. Ifran Khan et al., Defendants Case No.: No. BC615636
Rosenfeld Deposition, 1-26-2019
In The Superior Court of the State of California In And For The County Of Los Angeles — Santa Monica The San Gabriel Valley Council of Governments et al. vs El Adobe Apts. Inc. et al., Defendants Case No.: No. BC646857
Rosenfeld Deposition, 10-6-2018; Trial 3-7-19
In United States District Court For The District of Colorado Bells et al. Plaintiff vs. The 3M Company et al., Defendants Case: No 1:16-cv-02531-RBJ
Rosenfeld Deposition, 3-15-2018 and 4-3-2018
In The District Court Of Regan County, Texas, 112th Judicial District Phillip Bales et al., Plaintiff vs. Dow Agrosciences, LLC, et al., Defendants Cause No 1923
Rosenfeld Deposition, 11-17-2017
In The Superior Court of the State of California In And For The County Of Contra Costa Simons et al., Plaintiffs vs. Chevron Corporation, et al., Defendants Cause No C12-01481
Rosenfeld Deposition, 11-20-2017
In The Circuit Court Of The Twentieth Judicial Circuit, St Clair County, Illinois Martha Custer et al., Plaintiff vs. Cerro Flow Products, Inc., Defendants Case No.: No. 0i9 -L-2295
Rosenfeld Deposition, 8-23-2017
In The Superior Court of the State of California, For The County of Los Angeles Warrn Gilbert and Penny Gilber, Plaintiff vs. BMW of North America LLC Case No.: LC102019 (c/w BC582154)
Rosenfeld Deposition, 8-16-2017, Trail 8-28-2018
In the Northern District Court of Mississippi, Greenville Division Brenda J. Cooper, et al., Plaintiffs, vs. Meritor Inc., et al., Defendants Case Number: 4:16-cv-52-DMB-JVM
Rosenfeld Deposition: July 2017
Paul E. Rosenfeld, Ph.D.

Page 8 of 10 ends

In The Superior Court of the State of Washington, County of Snohomish Michael Davis and Julie Davis et al., Plaintiff vs. Cedar Grove Composting Inc., Defendants Case No.: No. 13-2-03987-5
Rosenfeld Deposition, February 2017
Trial, March 2017
In The Superior Court of the State of California, County of Alameda Charles Spain., Plaintiff vs. Thermo Fisher Scientific, et al., Defendants Case No.: RG14711115
Rosenfeld Deposition, September 2015
In The Iowa District Court hi And For Poweshiek County
Russell D. Winburn, et al., Plaintiffs vs. Doug Hoksbergen, et al., Defendants Case No.: LALA002187
Rosenfeld Deposition, August 2015
In The Iowa District Court For Wapello County
Jerry Dovico, et al., Plaintiffs vs. Valley View Sine LLC, et al., Defendants Law No,: LALA105144 - Division A
Rosenfeld Deposition, August 2015
In The Iowa District Court For Wapello County
Doug Pauls, et al.,, et al., Plaintiffs vs. Richard Warren, et al., Defendants Law No,: LALA105144 - Division A
Rosenfeld Deposition, August 2015
In The Circuit Court of Ohio County, West Virginia
Robert Andrews, et al. v. Antero, et al.

Civil Action NO. 14-C-30000
Rosenfeld Deposition, June 2015
In The Third Judicial District County of Dona Ana, New Mexico Betty Gonzalez, et al. Plaintiffs vs. Del Oro Dairy, Del Oro Real Estate LLC, Jerry Settles and Deward DeRuyter, Defendants
Rosenfeld Deposition: July 2015
In The Iowa District Court For Muscatine County
Laurie Freeman et. al. Plaintiffs vs. Grain Processing Corporation, Defendant Case No 4980
Rosenfeld Deposition: May 2015
In the Circuit Court of the 1711i Judicial Circuit, in and For Broward County, Florida Walter Hinton, et. al. Plaintiff, vs. City of Fort Lauderdale, Florida, a Municipality, Defendant.

Case Number CACE07030358 (26)
Rosenfeld Deposition: December 2014
In the United States District Court Western District of Oklahoma Tommy McCarty, et al., Plaintiffs, v. Oklahoma City Landfill, LLC d/b/a Southeast Oklahoma City Landfill, et al. Defendants.

Case No. 5:12-cv-01152-C
Rosenfeld Deposition: July 2014
Paul E. Rosenfeld, Ph.D.

Page 9 of 10 ends

In the County Court of Dallas County Texas
Lisa Parr et al, Plaintiff, vs. Aruba et al, Defendant.

Case Number cc -11-01650-E
Rosenfeld Deposition: March and September 2013
Rosenfeld Trial: April 2014
In the Court of Common Pleas of Tuscarawas County Ohio
John Michael Abicht, et al., Plaintiffs, vs. Republic Services, Inc., et al., Defendants Case Number: 2008 CT 10 0741 (Cons. w/ 2009 CV 10 0987) Rosenfeld Deposition: October 2012
In the United States District Court of Southern District of Texas Galveston Division Kyle Cannon, Eugene Donovan, Genaro Ramirez, Carol Sassler, and Harvey Walton, each Individually and on behalf of those similarly situated, Plaintiffs, vs. BP Products North America, Inc., Defendant.

Case 3:10-cv-00622
Rosenfeld Deposition: February 2012
Rosenfeld Trial: April 2013
In the Circuit Court of Baltimore County Maryland
Philip E. Cvach, II et al., Plaintiffs vs. Two Farms, Inc. d/b/a Royal Farms, Defendants Case Number: 03-C-12-012487 OT
Rosenfeld Deposition: September 2013
Paul E. Rosenfeld, Ph.D.

Page 10 of 10 ends

EXHIBIT C

SWAPS
Technical Consultation, Data Analysis and
Litigation Support for the Environment
Matthew F. Hagemann, P.G., C.Hg., QSD, QSP
1640 5th St.., Suite 204 Santa
Santa Monica, California 90401
Tel: (949) 887-9013
Email: [email protected]
Geologic and Hydrogeologic Characterization
Industrial Stormwater Compliance
Investigation and Remediation Strategies
Litigation Support and Testifying Expert
CEQA Review
Education:

M.S. Degree, Geology, California State University Los Angeles, Los Angeles, CA, 1984.

B.A. Degree, Geology, Humboldt State University, Arcata, CA, 1982.

Professional Certifications:

California Professional Geologist
California Certified Hydrogeologist
Qualified SWPPP Developer and Practitioner
Professional Experience:

Matt has 25 years of experience in environmental policy, assessment and remediation. He spent nine years with the U.S. EPA in the RCRA and Superfund programs and served as EPA's Senior Science Policy Advisor in the Western Regional Office where he identified emerging threats to groundwater from perchlorate and MTBE. While with EPA, Matt also served as a Senior Hydrogeologist in the oversight of the assessment of seven major military facilities undergoing base closure. He led numerous enforcement actions under provisions of the Resource Conservation and Recovery Act (RCRA) while also working with permit holders to improve hydrogeologic characterization and water quality monitoring.

Matt has worked closely with U.S. EPA legal counsel and the technical staff of several states in the application and enforcement of RCRA, Safe Drinking Water Act and Clean Water Act regulations. Matt has trained the technical staff in the States of California, Hawaii, Nevada, Arizona and the Territory of Guam in the conduct of investigations, groundwater fundamentals, and sampling techniques.

Positions Matt has held include:
• Founding Partner, Soil/Water/Air Protection Enterprise (SWAPE) (2003 - present); • Geology Instructor, Golden West College, 2010 - 2014; • Senior Environmental Analyst, Komex H2O Science, Inc. (2000 -- 2003);

• Executive Director, Orange Coast Watch (2001 - 2004); • Senior Science Policy Advisor and Hydrogeologist, U.S. Environmental Protection Agency (1989- 1998);
• Hydrogeologist, National Park Service, Water Resources Division (1998 — 2000); • Adjunct Faculty Member, San Francisco State University, Department of Geosciences (1993 — 1998);
• Instructor, College of Marin, Department of Science (1990 —1995); • Geologist, U.S. Forest Service (1986 -1998); and
• Geologist, Dames & Moore (1984 -1986).

Senior Regulatory and Litigation Support Analyst:

With SWAPE, Matt's responsibilities have included:
• Lead analyst and testifying expert in the review of over 100 environmental impact reports since 2003 under CEQA that identify significant issues with regard to hazardous waste, water resources, water quality, air quality, Valley Fever, greenhouse gas emissions, and geologic hazards. Make recommendations for additional mitigation measures to lead agencies at the local and county level to include additional characterization of health risks and implementation of protective measures to reduce worker exposure to hazards from toxins and Valley Fever.
• Stormwater analysis, sampling and best management practice evaluation at industrial facilities. • Manager of a project to provide technical assistance to a community adjacent to a former Naval shipyard under a grant from the U.S. EPA.
• Technical assistance and litigation support for vapor intrusion concerns. • Lead analyst and testifying expert in the review of environmental issues in license applications for large solar power plants before the California Energy Commission. • Manager of a project to evaluate numerous formerly used military sites in the western U.S. • Manager of a comprehensive evaluation of potential sources of perchlorate contamination in Southern California drinking water wells.
• Manager and designated expert for litigation support under provisions of Proposition 65 in the review of releases of gasoline to sources drinking water at major refineries and hundreds of gas stations throughout California.
• Expert witness on two cases involving MTBE litigation. • Expert witness and litigation support on the impact of air toxins and hazards at a school. • Expert witness in litigation at a former plywood plant.

With Komex H2O Science Inc., Matt's duties included the following:
• Senior author of a report on the extent of perchlorate contamination that was used in testimony by the former U.S. EPA Administrator and General Counsel. • Senior researcher in the development of a comprehensive, electronically interactive chronology of MTBE use, research, and regulation.
• Senior researcher in the development of a comprehensive, electronically interactive chronology of perchlorate use, research, and regulation.
• Senior researcher in a study that estimates nationwide costs for MTBE remediation and drinking water treatment, results of which were published in newspapers nationwide and in testimony against provisions of an energy bill that would limit liability for oil companies. • Research to support litigation to restore drinking water supplies that have been contaminated by MTBE in California and New York.
2 • Expert witness testimony in a case of oil production -related contamination in Mississippi. • Lead author for a multi -volume remedial investigation report for an operating school in Los Angeles that met strict regulatory requirements and rigorous deadlines. 3 • Development of strategic approaches for cleanup of contaminated sites in consultation with clients and regulators.

Executive Director:

As Executive Director with Orange Coast Watch, Matt led efforts to restore water quality at Orange County beaches from multiple sources of contamination including urban runoff and the discharge of wastewater. In reporting to a Board of Directors that included representatives from leading Orange County universities and businesses, Matt prepared issue papers in the areas of treatment and disinfection of wastewater and control of the discharge of grease to sewer systems. Matt actively participated in the development of countywide water quality permits for the control of urban runoff and permits for the discharge of wastewater. Matt worked with other nonprofits to protect and restore water quality, including Surfrider, Natural Resources Defense Council and Orange County CoastKeeper as well as with business institutions including the Orange County Business Council.

Hydrogeology:

As a Senior Hydrogeologist with the U.S. Environmental Protection Agency, Matt led investigations to characterize and cleanup closing military bases, including Mare Island Naval Shipyard, Hunters Point Naval Shipyard, Treasure Island Naval Station, Alameda Naval Station, Moffett Field, Mather Army Airfield, and Sacramento Army Depot. Specific activities were as follows:
• Led efforts to model groundwater flow and contaminant transport, ensured adequacy of monitoring networks, and assessed cleanup alternatives for contaminated sediment, soil, and groundwater.
• Initiated a regional program for evaluation of groundwater sampling practices and laboratory analysis at military bases.
• Identified emerging issues, wrote technical guidance, and assisted in policy and regulation development through work on four national U.S. EPA workgroups, including the Superfund Groundwater Technical Forum and the Federal Facilities Forum.

At the request of the State of Hawaii, Matt developed a methodology to determine the vulnerability of groundwater to contamination on the islands of Maui and Oahu. He used analytical models and a GIS to show zones of vulnerability, and the results were adopted and published by the State of Hawaii and County of Maui.

As a hydrogeologist with the EPA Groundwater Protection Section, Matt worked with provisions of the Safe Drinking Water Act and NEPA to prevent drinking water contamination. Specific activities included the following:
• Received an EPA Bronze Medal for his contribution to the development of national guidance for the protection of drinking water.
• Managed the Sole Source Aquifer Program and protected the drinking water of two communities through designation under the Safe Drinking Water Act. He prepared geologic reports, conducted public hearings, and responded to public comments from residents who were very concerned about the impact of designation.
4 • Reviewed a number of Environmental Impact Statements for planned major developments, including large hazardous and solid waste disposal facilities, mine reclamation, and water transfer.

Matt served as a hydrogeologist with the RCRA Hazardous Waste program. Duties were as follows:
• Supervised the hydrogeologic investigation of hazardous waste sites to determine compliance with Subtitle C requirements.
• Reviewed and wrote "part B" permits for the disposal of hazardous waste. • Conducted RCRA Corrective Action investigations of waste sites and led inspections that formed the basis for significant enforcement actions that were developed in close coordination with U.S.

EPA legal counsel.
• Wrote contract specifications and supervised contractor's investigations of waste sites.

With the National Park Service, Matt directed service -wide investigations of contaminant sources to prevent degradation of water quality, including the following tasks:
• Applied pertinent laws and regulations including CERCLA, RCRA, NEPA, NRDA, and the Clean Water Act to control military, mining, and landfill contaminants. • Conducted watershed -scale investigations of contaminants at parks, including Yellowstone and Olympic National Park.
• Identified high -levels of perchlorate in soil adjacent to a national park in New Mexico and advised park superintendent on appropriate response actions under CERCLA. • Served as a Park Service representative on the Interagency Perchlorate Steering Committee, a national workgroup.
• Developed a program to conduct environmental compliance audits of all National Parks while serving on a national workgroup.
• Co-authored two papers on the potential for water contamination from the operation of personal watercraft and snowmobiles, these papers serving as the basis for the development of nation- wide policy on the use of these vehicles in National Parks. • Contributed to the Federal Multi -Agency Source Water Agreement under the Clean Water Action Plan.

Policy:

Served senior management as the Senior Science Policy Advisor with the U.S. Environmental Protection Agency, Region 9. Activities included the following:
• Advised the Regional Administrator and senior management on emerging issues such as the potential for the gasoline additive MTBE and ammonium perchlorate to contaminate drinking water supplies.
• Shaped EPA's national response to these threats by serving on workgroups and by contributing to guidance, including the Office of Research and Development publication, Oxygenates in Water: Critical Information and Research Needs.
• Improved the technical training of EPA's scientific and engineering staff. • Earned an EPA Bronze Medal for representing the region's 300 scientists and engineers in negotiations with the Administrator and senior management to better integrate scientific principles into the policy -making process.
• Established national protocol for the peer review of scientific documents. 5 Geology:

With the U.S. Forest Service, Matt led investigations to determine hillslope stability of areas proposed for timber harvest in the central Oregon Coast Range. Specific activities were as follows:
• Mapped geology in the field, and used aerial photographic interpretation and mathematical models to determine slope stability.
• Coordinated his research with community members who were concerned with natural resource protection.
• Characterized the geology of an aquifer that serves as the sole source of drinking water for the city of Medford, Oregon.

As a consultant with Dames and Moore, Matt led geologic investigations of two contaminated sites (later listed on the Superfund NPL) in the Portland, Oregon, area and a large hazardous waste site in eastern Oregon. Duties included the following:
• Supervised year -long effort for soil and groundwater sampling. • Conducted aquifer tests.
• Investigated active faults beneath sites proposed for hazardous waste disposal.

Teaching:

From 1990 to 1998, Matt taught at least one course per semester at the community college and university levels:
• At San Francisco State University, held an adjunct faculty position and taught courses in environmental geology, oceanography (lab and lecture), hydrogeology, and groundwater contamination.
• Served as a committee member for graduate and undergraduate students. • Taught courses in environmental geology and oceanography at the College of Marin.

Matt taught physical geology (lecture and lab and introductory geology at Golden West College in Huntington Beach, California from 2010 to 2014.

Invited Testimony, Reports, Papers and Presentations:

Hagemann, M.F., 2008. Disclosure of Hazardous Waste Issues under CEQA. Presentation to the Public Environmental Law Conference, Eugene, Oregon.

Hagemann, M.F., 2008. Disclosure of Hazardous Waste Issues under CEQA. Invited presentation to U.S.

EPA Region 9, San Francisco, California.

Hagemann, M.F., 2005. Use of Electronic Databases in Environmental Regulation, Policy Making and Public Participation. Brownfields 2005, Denver, Coloradao.

Hagemann, M.F., 2004. Perchlorate Contamination of the Colorado River and Impacts to Drinking Water in Nevada and the Southwestern U.S. Presentation to a meeting of the American Groundwater Trust, Las Vegas, NV (served on conference organizing committee).

Hagemann, M.F., 2004. Invited testimony to a California Senate committee hearing on air toxins at schools in Southern California, Los Angeles.
6 Brown, A., Farrow, J., Gray, A. and Hagemann, M., 2004. An Estimate of Costs to Address MTBE Releases from Underground Storage Tanks and the Resulting Impact to Drinking Water Wells.

Presentation to the Ground Water and Environmental Law Conference, National Groundwater Association.

Hagemann, M.F., 2004. Perchlorate Contamination of the Colorado River and Impacts to Drinking Water in Arizona and the Southwestern U.S. Presentation to a meeting of the American Groundwater Trust, Phoenix, AZ (served on conference organizing committee).

Hagemann, M.F., 2003. Perchlorate Contamination of the Colorado River and Impacts to Drinking Water in the Southwestern U.S. Invited presentation to a special committee meeting of the National Academy of Sciences, Irvine, CA.

Hagemann, M.F., 2003. Perchlorate Contamination of the Colorado River. Invited presentation to a tribal EPA meeting, Pechanga, CA.

Hagemann, M.F., 2003. Perchlorate Contamination of the Colorado River. Invited presentation to a meeting of tribal repesentatives, Parker, AZ.

Hagemann, M.F., 2003. Impact of Perchlorate on the Colorado River and Associated Drinking Water Supplies. Invited presentation to the Inter -Tribal Meeting, Torres Martinez Tribe.

Hagemann, M.F., 2003. The Emergence of Perchlorate as a Widespread Drinking Water Contaminant.

Invited presentation to the U.S. EPA Region 9.

Hagemann, M.F., 2003. A Deductive Approach to the Assessment of Perchlorate Contamination. Invited presentation to the California Assembly Natural Resources Committee.

Hagemann, M.F., 2003. Perchlorate: A Cold War Legacy in Drinking Water. Presentation to a meeting of the National Groundwater Association.

Hagemann, M.F., 2002. From Tank to Tap: A Chronology of MTBE in Groundwater. Presentation to a meeting of the National Groundwater Association.

Hagemann, M.F., 2002. A Chronology of MTBE in Groundwater and an Estimate of Costs to Address Impacts to Groundwater. Presentation to the annual meeting of the Society of Environmental Journalists.

Hagemann, M.F., 2002. An Estimate of the Cost to Address MTBE Contamination in Groundwater (and Who Will Pay). Presentation to a meeting of the National Groundwater Association.

Hagemann, M.F., 2002. An Estimate of Costs to Address MTBE Releases from Underground Storage Tanks and the Resulting Impact to Drinking Water Wells. Presentation to a meeting of the U.S. EPA and State Underground Storage Tank Program managers.

Hagemann, M.F., 2001. From Tank to Tap: A Chronology of MTBE in Groundwater. Unpublished report.
7 Hagemann, M.F., 2001. Estimated Cleanup Cost for MTBE in Groundwater Used as Drinking Water.

Unpublished report.

Hagemann, M.F., 2001. Estimated Costs to Address MTBE Releases from Leaking Underground Storage Tanks. Unpublished report.

Hagemann, M.F., and VanMouwerik, M., 1999. Potential W a t e r Quality Concerns Related to Snowmobile Usage. Water Resources Division, National Park Service, Technical Report.

VanMouwerik, M. and Hagemann, M.F. 1999, Water Quality Concerns Related to Personal Watercraft Usage. Water Resources Division, National Park Service, Technical Report.

Hagemann, M.F., 1999, Is Dilution the Solution to Pollution in National Parks? The George Wright Society Biannual Meeting, Asheville, North Carolina.

Hagemann, M.F., 1997, The Potential for MTBE to Contaminate Groundwater. U.S. EPA Superfund Groundwater Technical Forum Annual Meeting, Las Vegas, Nevada.

Hagemann, M.F., and Gill, M., 1996, Impediments to Intrinsic Remediation, Moffett Field Naval Air Station, Conference on Intrinsic Remediation of Chlorinated Hydrocarbons, Salt Lake City.

Hagemann, M.F., Fukunaga, G.L., 1996, The Vulnerability of Groundwater to Anthropogenic Contaminants on the Island of Maui, Hawaii. Hawaii Water Works Association Annual Meeting, Maui, October 1996.

Hagemann, M. F., Fukanaga, G. L., 1996, Ranking Groundwater Vulnerability in Central Oahu, Hawaii. Proceedings, Geographic Information Systems in Environmental Resources Management, Air and Waste Management Association Publication VIP -61.

Hagemann, M.F., 1994. Groundwater Characterization and Cleanup at Closing Military Bases in California. Proceedings, California Groundwater Resources Association Meeting.

Hagemann, M.F. and Sabol, M.A., 1993. Role of the U.S. EPA in the High Plains States Groundwater Recharge Demonstration Program. Proceedings, Sixth Biennial Symposium on the Artificial Recharge of Groundwater.

Hagemann, M.F., 1993. U.S. EPA Policy on the Technical Impracticability of the Cleanup of DNAPL- contaminated Groundwater. California Groundwater Resources Association Meeting. 8 Hagemann, M.F., 1992. Dense Nonaqueous Phase Liquid Contamination of Groundwater: An Ounce of Prevention... Proceedings, Association of Engineering Geologists Annual Meeting, v. 35.

Other Experience:

Selected as subject matter expert for the California Professional Geologist licensing examination, 2009- 2011.
9 EXHIBIT D

FEDERAL TRANSIT ADMINISTRATION
Transit Noise and Vibration Impact
Assessment Manual
SEPTEMBER 2018
FTA Report No. 0123
Federal Transit Administration

PREPARED BY
John A. Volpe National Transportation Systems Center
a
U.S. Department of Transportation
Federal Transit Administration

COVER PHOTO
Courtesy of Edwin Adilson Rodriguez, Federal Transit Administration

DISCLAIMER
This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The United States Government assumes no liability for its contents or use thereof. The United States Government does not endorse products or manufacturers. Trade or manufacturers' names appear herein solely because they are considered essential to the objective of this report. ii

Transit Noise and
Vibration Impact
Assessment Manual
SEPTEMBER 2018
FTA Report No. 0123

PREPARED BY
Antoinette Quagliata
Federal Transit Administration
Office of Planning and Environment
Meghan Ahearn
Eric Boeker
Christopher Roof
John A. Volpe National Transportation
Systems Center
Cambridge, MA 02142
Lance Meister
Herbert Singleton
Cross Spectrum Acoustics
East Longmeadow, MA 01028
Utah: Salt Lake City, UT 84102

SPONSORED BY
Federal Transit Administration
Office of Planning and Environment
U.S. Department of Transportation
1200 New Jersey Avenue, SE
Washington, DC 20590
iii

Metric Conversion Table

SYMBOL WHEN YOU KNOW MULTIPLY BY

TO FIND SYMBOL
LENGTH
in
inches 25.4
millimeters mm
ft
feet 0.305
meters m
yd
yards 0.914
meters m
mi
miles 1.61
kilometers km
VOLUME
fl oz fluid ounces 29.57
milliliters mL
gal
gallons 3.785
liters L
ft3 cubic feet

0.028 cubic meters
m'
yd3 cubic yards

0.765 cubic meters
m
NOTE: volumes greater than 1000 L shall be shown in m'
MASS
oz
ounces 28.35
grams g
Ib
pounds 0.454
kilograms kg
T
short tons (2000 Ib) 0.907
megagrams
(or "metric ton")
Mg (or "t")
TEMPERATURE (exact degrees)
°F Fahrenheit
5 (F-32)/9
or (F-32)/1.8
Celsius
"C
iv

�1
�
Form Approved OMB No.
0704-0188
The public reporting burden for this collection of information is estimated to average I hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.

PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS.

I. REPORT DATE
September 2018

2. REPORT TYPE
Final

3. DATES COVERED

4. TITLE AND SUBTITLE
Transit Noise and Vibration Impact Assessment Manual
5a. CONTRACT NUMBER
5b. GRANT NUMBER
5c. PROGRAM ELEMENT
NUMBER

6. AUTHOR(S)
Quagliata, Antoinette (FTA)
Ahearn, Meghan (VOLPE)
Boeker, Eric (VOLPE)
Roof, Christopher (VOLPE)
Meister, Lance (CSA)
Singleton, Herbert (CSA)
5d. PROJECT NUMBER
TF09A I
5e. TASK NUMBER
NLJ56
5f. WORK UNIT NUMBER

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)
U.S. Department of Transportation
Volpe National Transportation Systems Center
55 Broadway
Cambridge, MA 02142

8. PERFORMING

ORGANIZATION REPORT
NUMBER
FTA Report No. 0123

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) U.S. Department of Transportation
Federal Transit Administration
Office of Planning and Environment
1200 New Jersey Avenue, S.E.

Washington, DC 20590
I O. SPONSOR/MONITOR'S

ACRONYM(S)
FTA
I 1. SPONSOR/MONITOR'S

REPORT NUMBER(S)
FTA Report No. 0123

12. DISTRIBUTION/AVAILABILITY STATEMENT
This document is available through the FTA website: http://www.fta.dot.gov/ .

13. SUPPLEMENTARY NOTES
I4. ABSTRACT
This report is the third edition of a guidance manual originally issued in 1995. It includes clarifications to existing policy and updates to outdated references where applicable. Topics presented in this manual include procedures for predicting and assessing noise and vibration impacts of proposed transit projects for different stages of project development and different levels of analysis. Additional topics include descriptions of noise and vibration mitigation measures, construction noise and vibration, and how to present these analyses in the Federal Transit Administration's environmental documents. This guidance is for technical specialists who conduct the analyses, as well as project sponsor staff, Federal agency reviewers, and members of the general public who may be affected by the projects.

15. SUBJECT TERMS
Transit noise and vibration analysis, noise and vibration impact criteria, noise and vibration mitigation measures, environmental impact assessment, Nation Environmental Policy Act compliance.

16. SECURITY CLASSIFICATION OF:

I 7.

LIMITATION
OF

ABSTRACT

18. NUMBER

OF PAGES
258
I9a. NAME OF RESPONSIBLE PERSON
a. REPORT
Unclassified
b. ABSTRACT
Unclassified
c. THIS
PAGE
Unclassified
I9b. TELEPHONE NUMBER
(Include area code)
V

Table of Contents
SECTION I: INTRODUCTION
I.I PURPOSE

1.2 ORGANIZATION OF THE MANUAL 2
SECTION 2: PROJECT CLASS OF ACTION AND PLANNING 3

2. I PROJECT CLASS OF ACTION 3

2.2 PROJECT PLANNING AND DEVELOPMENT 4

2.3 MITIGATION POLICY CONSIDERATIONS 5
SECTION 3: TRANSIT NOISE 9

3.1 NOISE METRICS 10

3.2 SOURCES OF TRANSIT VEHICLE NOISE 10

3.3 PATHS OF TRANSIT NOISE FROM SOURCE TO RECEIVER 14

3.4 RECEIVER RESPONSE TO TRANSIT NOISE 16
SECTION 4: NOISE IMPACT ANALYSIS 19

4. I DETERMINE NOISE IMPACT CRITERIA 20
Step I: Identify Project Type. 2 I
Step 2: Choose Land Use Category for FTA Criteria 23
Step 3: Determine Appropriate FTA Criteria Presentation 25

4.2 DETERMINE NOISE ANALYSIS LEVEL 3 I

4.3 EVALUATE IMPACT: NOISE SCREENING PROCEDURE 33
Step I: Identify Project Type 33
Step 2: Determine the Screening Distance 33
Step 3: Identify Study Area 34
Step 4: Locate Noise -Sensitive Land Uses 34

4.4 EVALUATE IMPACT: GENERAL NOISE ASSESSMENT 37
Step I: Identify Noise -Sensitive Receivers 38
Step 2: Determine Project Noise Source Reference Levels 39 Step 3: Estimate Project Noise Exposure by Distance 48
Step 4: Combine Noise Exposure from All Sources 49
Step 5: Estimate Existing Noise Exposure 50
Step 6: Inventory Noise Impacts 52
Step 7: Determine Noise Mitigation Needs 54

4.5 EVALUATE IMPACT: DETAILED NOISE ANALYSIS 64
Step I: Identify Noise -Sensitive Receivers 66
Step 2: Determine Project Noise Source Reference Leve/s 70 Step 3: Determine Propagation Characteristics 84
Step 4: Combine Noise Exposure from All Sources 91
Step 5: Determine Existing Noise Exposure 92
Step 6: Assess Noise Impact 95
Step 7: Determine Noise Mitigation Measures 97
SECTION 5: TRANSIT VIBRATION 109

5.1 GROUND -BORNE VIBRATION AND NOISE METRICS 1 10

5.2 SOURCES OF TRANSIT GROUND -BORNE VIBRATION AND NOISE 1 12

5.3 PATHS OF TRANSIT GROUND -BORNE VIBRATION AND NOISE 1 16 vi

5.4 RECEIVER FACTORS THAT INFLUENCE GROUND -BORNE VIBRATION AND NOISE 1 17

5.5 HUMAN RESPONSE TO TRANSIT GROUND -BORNE VIBRATION AND NOISE 1 17 SECTION 6: VIBRATION IMPACT ANALYSIS 121

6. I DETERMINE VIBRATION ANALYSIS LEVEL 121

6.2 DETERMINE VIBRATION IMPACT CRITERIA 123
Option A: General Vibration Assessment Criteria 123
Step I: Land Use Categories 123
Step 2: Identify Event Frequency 125
Step 3: Apply Impact Criteria by Land Use and Event Frequency 125 Option B: Vibration Impact Criteria for a Detailed Vibration Analysis 130 Step I: Ground -Borne Vibration 130
Step 2: Ground -borne Noise 132

6.3 EVALUATE IMPACT: VIBRATION SCREENING PROCEDURE 132
Step I: Classify project vehicles 133
Step 2: Determine Project Type 134
Step 3: Determine Screening Distance 135
Step 4: Identify Vibration -Sensitive Land Uses 136

6.4 EVALUATE IMPACT: GENERAL VIBRATION ASSESSMENT 136
Step I: Select Base Curve for Ground Surface Vibration Level 136 Step 2: Apply Adjustments 139
Step 3: Inventory of Vibration Impact 147

6.5 EVALUATE IMPACT: DETAILED VIBRATION ANALYSIS 149
Step I: Characterize Existing Vibration Conditions 149
Step 2: Estimate Vibration Impact 152
Step 3: Assess Vibration Impact 165
Step 4: Determine Vibration Mitigation Measures 165
SECTION 7: NOISE AND VIBRATION DURING CONSTRUCTION I72

7. I CONSTRUCTION NOISE ASSESSMENT 172
Step I: Determine Level of Construction Noise Assessment 173 Step 2: Use a Qualitative Construction Noise Assessment to Estimate Construction Noise 174 Step 3: Use a Quantitative Construction Noise Assessment to Estimate Construction Noise 174 Step 4: Assess Construction Noise Impact 178
Step 5: Determine Construction Noise Mitigation Measures 179

7.2 CONSTRUCTION VIBRATION ASSESSMENT 182
Step I: Determine Level of Construction Vibration Assessment 182 Step 2: Use a Qualitative Construction Vibration Assessment 183 Step 3: Use a Quantitative Construction Vibration Assessment 183 Step 4: Assess Construction Vibration Impact 185
Step 5: Determine Construction Vibration Mitigation Measures 186 SECTION 8: DOCUMENTATION OF NOISE AND VIBRATION ASSESSMENT 188

8. I ENVIRONMENTAL DOCUMENT 188
Step I: Choose the information to include 189
Step 2: Organize information in the Environmental Document 190

8.2 TECHNICAL REPORT ON NOISE AND VIBRATION 192
VII

APPENDIX A GLOSSARY OF TERMS 195
APPENDIX B FUNDAMENTALS OF NOISE 200
B. I AMPLITUDE 200
B. I . I DECIBEL ADDITION 201
B.I.2 FREQUENCY 203
B. I .3 TIME PATTERN 205
B. I .4 NOISE METRICS 206
B. I.4. I A-wEIGHTED SOUND LEVEL: THE BASIC NOISE UNIT 206 B. I .4.2 MAXIMUM SOUND LEVEL (LMAx) DURING A SINGLE NOISE EVENT 207 B. I .4.3 SOUND EXPOSURE LEVEL (SEL): EXPOSURE FROM A SINGLE NOISE EVENT 208 B. I .4.4 EQUIVALENT SOUND LEVEL (LEQ(T)) 210
B. I.4.5 DAY -NIGHT SOUND LEVEL (LDN): 24 -HOUR EXPOSURE FROM ALL EVENTS 214 APPENDIX C BACKGROUND FOR TRANSIT NOISE IMPACT CRITERIA 217 C. I RELEVANT LITERATURE 217
C.2 BASIS FOR NOISE IMPACT CRITERIA CURVES 218
C.3 EQUATIONS FOR NOISE IMPACT CRITERIA CURVES 219
APPENDIX D CLUSTERING RECEIVERS OF INTEREST 221
APPENDIX E DETERMINING EXISTING NOISE 225
APPENDIX F COMPUTING SOURCE LEVELS FROM MEASUREMENTS 229 F. I HIGHWAY AND RAIL VEHICLE PASSBYS 229
F.2 STATIONARY SOURCES 233
F.3 LMAx FOR SINGLE TRAIN PASSBY 234

APPENDIX G NON-STANDARD MODELING PROCEDURES
AND METHODOLOGY 237
viii

List of Figures
Figure 3- I Source -Path -Receiver Framework 9
Figure 3-2 Sound Level Dependence on Speed I2
Figure 3-3 Attenuation Due to Distance (Divergence) 15
Figure 3-4 Attenuation due to Soft Ground 15
Figure 3-5 Noise Barrier Geometry I6
Figure 3-6 Community Reaction to New Noise, Relative to Existing Noise in a Residential Urban Environment I8
Figure 3-7 Community Annoyance Due to Noise I8
Figure 4- I Noise Impact Criteria Flow Chart by Project Segment 20 Figure 4-2 Noise Impact Criteria for Transit Projects 27 Figure 4-3 Increase in Cumulative Noise Levels Allowed by Criteria (Land Use Cat. I & 2) 30 Figure 4-4 Increase in Cumulative Noise Levels Allowed by Criteria (Land Use Cat. 3) 30 Figure 4-5 Procedure for General Noise Assessment 38
Figure 4-6 Curves for Estimating Exposure vs. Distance in General Noise Assessment 48 Figure 4-7 Noise Impacts of Hypothetical Commuter Rail 57 Figure 4-8 Example of Project for General Noise Assessment: Siting of Transit Center in Mixed Commercial/Residential Area 64
Figure 4-9 Procedure for Detailed Noise Analysis 66
Figure 4-10 Guide to Selecting Noise -Sensitive Receivers of Interest 67 Figure 4- I I Flow Diagram for Determining Project Noise at 50 ft 70 Figure 4-12 Flat Ground 86
Figure 4-13 Source in Shallow Cut 86
Figure 4-14 Elevated Receiver 86
Figure 4-15 Source in Sloped Cut 86
Figure 4-16 Source and Receiver Separated by Trench 86
Figure 4-17 Example Exposure vs. Distance Curves 88
Figure 4-18 Noise Barrier Parameter "P" 89
Figure 4- I9 Recommended Microphone Locations for Existing Noise Measurements 93 Figure 5- I Propagation of Ground -Borne Vibration into Buildings 109 Figure 5-2 Vibration Signal in Absolute Units I I I
Figure 5-3 Vibration Signal in RMS Velocity Decibels I I2 Figure 5-4 Typical Levels of Ground -Borne Vibration I I3 Figure 5-5 Response to Transit -Induced Residential Vibration I I9 Figure 6- I Existing Vibration Criteria Flow Chart 129
Figure 6-2 Criteria for Detailed Vibration Analysis 13 I Figure 6-3 Flow Chart of Vibration Screening Process 133 Figure 6-4 Generalized Ground Surface Vibration Curves I 37 Figure 6-5 Ground -Borne Vibration and Noise Model 154
Figure 6-6 Typical Force Densities for Rail Transit Vehicles, 40 mph 157 Figure 6-7 Typical Force Densities for LRT Vehicles, 40 mph 157 Figure 6-8 Test Configuration for Measuring Transfer Mobility 158 Figure 6-9 Example of Point -Source Transfer Mobility 159 Figure 6-10 Equipment Required for Field Testing and Laboratory Analysis 160 Figure 6- I I Analysis of Transfer Mobility I 6 I
Figure 6- I2 Schematic of Transfer Mobility Measurements Using a Line of Impacts 162 Figure 6-13 Example of Line -source Transfer Mobility 163 Figure 6- I4 Foundation Response for Various Types of Buildings 164 Figure B -I RMS Pressure Illustration 200
ix

Figure B-2 Graph for Approximate Decibel Addition 202
Figure B-3 Noise Spectrum of Transit Train on Curve and Elevated Structure 204 Figure B-4 A -Weighting Curve 205
Figure B-5 Typical A -weighted Sound Levels 207
Figure B-6 Typical Transit -Vehicle Passby 208
Figure B-7 Typical Fixed -Facility Noice Event 208
Figure B-8 An Energy Vice of Noise Events 210
Figure B-9 Typical Hourly Leq(ihr)'s 211
Figure B- I 0 Example A -weighted Sound Level Time Histories 212 Figure B- I I Typical Ldn's 214
Figure D- I Example of Receiver Map Showing Cluster Boundaries 224 x

List of Tables
Table 3-1 Noise Metrics I 0
Table 3-2 Sources of Transit Noise 13
Table 4- I Multimodal Project Noise Factors 22
Table 4-2 Multimodal Project Assessment Methods 22
Table 4-3 Land Use Categories and Metrics for Transit Noise Impact Criteria 23 Table 4-4 Levels of Impact 26
Table 4-5 Noise Levels Defining Impact for Transit Projects 28 Table 4-6 Noise Impact Criteria: Effect on Cumulative Noise Exposure 3 I Table 4-7 Screening Distance for Noise Assessments 35
Table 4-8 Assumptions for Screening Distances for Noise Assessments 36 Table 4-9 Reference SEL's 50 ft from Track and at 50 mph, One Vehicle 40 Table 4-10 Computation of Noise Exposure at 50 ft for Fixed -Guideway General Noise Assessment 42 Table 4- I I Source Reference Levels at 50 ft from Roadway, 50 mph 43 Table 4-I2 Computation of Leq(Ihr) and Ldn at 50 ft for Highway/Transit General Noise Assessment 44 Table 4-13 Source Reference Levels at 50 ft From the Center of Site, Stationary Sources 45 Table 4-I4 Computation of Leq(Ihr)and Ldn at 50 ft for Stationary Source General Noise Assessment47 Table 4-15 Distance Correction Factor Equations for General Noise Assessment 49 Table 4-16 Computing Total Noise Exposure 49
Table 4-17 Estimating Existing Noise Exposure for General Noise Assessment 52 Table 4-I8 Land Uses of Interest 68
Table 4-19 Sources of Transit Noise 71
Table 4-20 Source Reference SELs at 50 ft: Fixed -Guideway Sources at 50 mph 73 Table 4-21 Computation of Leq(Ihr) and Ldn at 50 ft: Fixed -Guideway Sources 76 Table 4-22 Source Reference SELs at 50 ft: Highway/Transit Sources at 50 mph 78 Table 4-23 Computation of Leq(Ihr) and Ldn at 50 ft: Highway/Transit Sources 80 Table 4-24 Source Reference SELs at 50 ft: Stationary Sources 82 Table 4-25 Computation of Leq(Ihr) and Ldn at 50 ft: Stationary Sources 83 Table 4-26 Ground Factor G, for Ground Attenuation 86
Table 4-27 Distance Correction Factor Equations for Detailed Noise Analysis 87 Table 4-28 Barrier Insertion Loss 88
Table 4-29 Attenuation due to Buildings 89
Table 4-30 Attenuation due to Trees 89
Table 4-3I Calculate Ldn or Leq(Ihr) 91
Table 4-32 Computing Total Noise Exposure 91
Table 4-33 Transit Noise Mitigation Measures — Source Treatments 97 Table 4-34 Transit Noise Mitigation Measures — Path Treatments 104 Table 4-35 Transit Noise Mitigation Measures — Receiver Treatments 106 Table 5- I Ground -borne Vibration and Noise Metrics 1 10 Table 5-2 Factors that Influence Levels of Ground -Borne Vibration and Noise at the Source I I4 Table 5-3 Factors that Influence Levels of Ground -borne Vibration and Noise along the Path 1 17 Table 5-4 Factors that Influence Levels of Ground -Borne Vibration and Noise at the Receiver 1 17 Table 5-5 Human Response to Different Levels of Ground -Borne Vibration and Noise 120 Table 6- I Land Use Categories for General Vibration Assessment Impact Criteria 124 Table 6-2 Event Frequency Definitions 125
Table 6-3 Indoor Ground -Borne Vibration (GBV) and Ground -Borne Noise (GBN) Impact Criteria for General Vibration Assessment 126
Table 6-4 Indoor Ground -Borne Vibration and Noise Impact Criteria for Special Buildings 126 xi

Table 6-5 Impact Criteria Considering Existing Conditions 128 Table 6-6 Interpretation of Vibration Criteria for Detailed Vibration Analysis 131 Table 6-7 Project Types for Vibration Screening Procedure 135 Table 6-8 Screening Distances for Vibration Assessments 136 Table 6-9 Ground Surface Vibration Level Base Curve Descriptions 137 Table 6-10 Generalized Ground Surface Vibration Equations 138 Table 6- I I Source Adjustment Factors for Generalized Predictions of GB Vibration and Noise 140 Table 6-12 Path Adjustment Factors for Generalized Predictions of GB Vibration and Noise 143 Table 6-13 Receiver Adjustment Factors for Generalized Predictions of GB Vibration and Noise 145 Table 6-14 Conversion to Ground -borne Noise 146
Table 7- I Construction Equipment Noise Emission Levels 176 Table 7-2 General Assessment Construction Noise Criteria 179 Table 7-3 Detailed Analysis Construction Noise Criteria 179 Table 7-4 Vibration Source Levels for Construction Equipment 184 Table 7-5 Construction Vibration Damage Criteria 186
Table C- I Threshold of Moderate and Severe Impacts 220 Table F- I Conversion to Source Reference Levels at 50 ft — Highway and Rail Sources 23 I Table F-2 Conversion to Source Reference Levels at 50 ft — Stationary Sources 234 Table F-3 Conversion to Lmax at the Receiver, for a Single Train Passby 235 xii

List of Examples
Example 4- I General Noise Assessment — Commuter Rail 54 Example 4-2 General Noise Assessment — Highway/Transit 59 Example 4-3 General Noise Assessment — BRT System 60
Example 4-4 General Noise Assessment — Transit Center 62 Example 4-5 Detailed Noise Analysis — Fixed Guideway Noise Sources 77 Example 4-6 Detailed Noise Analysis — Highway Transit Noise Sources 80 Example 4-7 Detailed Noise Analysis — Stationary Noise Sources 84 Example 4-8 Detailed Noise Analysis — Exposure Vs. Distance Curve 87 Example 4-9 Detailed Noise Analysis — Shielding 89
Example 4-10 Detailed Noise Analysis — Combine Sources 91 Example 6- I General Vibration Assessment — LRT 148
Example B- I Decibel Addition — Identical Buses 203
Example B-2 Decibel Addition — Two Sources 203
Example D-1 Clustering Receivers 223
Example F- I Calculate Selref — Locomotives 232
Example F-2 Calculate Selref — Rail Cars 232
Example F-3 Calculate Selref — Bus 233
Example F-4 Calculate Selref — Signal Crossing 234
Example F-5 Calculate Lmax — Train Passby 236

Abstract
This report is the third edition of a guidance manual originally issued in 1995. It includes clarifications to existing policy and updates to outdated references where applicable. Topics presented in this manual include procedures for predicting and assessing noise and vibration impacts of proposed transit projects for different stages of project development and different levels of analysis. Additional topics include descriptions of noise and vibration mitigation measures, construction noise and vibration, and how to present these analyses in the Federal Transit Administration's environmental documents. This guidance is for technical specialists who conduct the analyses, as well as project sponsor staff, Federal agency reviewers, and members of the general public who may be affected by the projects.

Acknowledgments
The original 1995 version of this manual was developed by the firm Harris Miller Miller & Hanson Inc. (HMMH) and peer -reviewed by a group of specialists in the fields of acoustics and environmental planning and analysis. HMMH updated the original manual in 2006.

The updates for this current version were provided by the John A. Volpe National Transportation Systems Center, Cross Spectrum Acoustics, and FTA, and it was peer -reviewed by a panel of experts.

The U.S. Department of Transportation FTA Office of Planning and Environment wishes to thank the following for their participation in the peer review of this manual:
■ Scott Edwards
■ Anthony Evans
■ Timothy Johnson
■ Shannon McKenna
■ Lance Meister
■ James Nelson
■ Anthony Joseph Ossi
■ Shankar Rajaram
■ Judith Rochat
■ Jason Ross
■ Hugh Saurenman
■ Herbert Singleton
■ David Towers
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TRANSIT NOISE AND VIBRATION IMPACT ASSESSMENT MANUAL
SECTION Introduction
I
I . I Purpose
The Council on Environmental Quality (CEQ) regulations for implementing the procedural provisions of the National Environmental Policy Act of 1969 (NEPA)(12) require that a federally -funded project be assessed for its impact on the human and natural environment prior to implementation. The Federal Transit Administration (FTA), in conjunction with the Federal Highway Administration (FHWA), has issued detailed regulations implementing NEPA for transit and highway projects. The regulations are codified in part 771 of title 23, Code of Federal Regulations, and are titled "Environmental Impact and Related Procedures." (23 CFR part 771).(3)
The Federal Transit Administration (FTA) provides financial assistance for a range of public transportation projects from new rail rapid transit (RRT) systems to bus maintenance facilities and vehicle purchases. As required by NEPA and its implementing regulations, each project must undergo environmental review.

Noise and vibration are sometimes among the major concerns regarding the effects of a transit project on the surrounding community and are key elements of the environmental impact assessment process for public transportation projects. A transit system is often placed near population centers by necessity and may cause noise and vibration at nearby residences and other sensitive types of land use.

This manual provides technical guidance for conducting noise and vibration analyses for transit projects, as well as direction regarding preparation of the information for FTA's environmental documents. Some situations may not be explicitly covered in this manual; the exercise of professional judgment may be required to extend the basic methods in these cases and frequent consultation with FTA staff is important to ensure the methods used meet the requirements for environmental reviews. See Appendix G for information on using non- standard modeling procedures.

In general, the noise and vibration impact assessment process for projects includes the following steps:

1. Determine appropriate impact criteria (Section 4.1).

2. Conduct screening and determine appropriate level of noise analysis, analyze project noise impacts, and evaluate mitigation options if appropriate (Sections 4.2-4.5).

3. Determine appropriate level of vibration analysis, analyze project vibration impacts, and evaluate mitigation options if appropriate (Sections 6.I-6.5).

4. Analyze construction noise and vibration impacts (Section 7).

5. Document findings (Section 8).

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1.2 Organization of the Manual
This guidance manual is organized by the following recommended analysis workflow. A glossary of terms used throughout this manual is available in Appendix A. Detailed information on the fundamentals of noise, noise impact criteria, clustering receivers, determining existing noise, computing source levels from measurements, and using non-standard methodology is available in the appendices.

Section 2: Project Class of Action and Planning — This section describes the first step in the analysis process that is applicable to both noise and vibration analyses.

Section 3: Transit Noise — This section provides the reader with background information specific to transit noise.

Section 4: Noise Impact Analysis — This section provides a general outline of the entire noise impact analysis process: guidelines on determining noise impact criteria, methods for choosing the appropriate level of noise analysis ("Screening," "General," or "Detailed"), steps for evaluating noise impacts with the Noise Screening Procedure (a simplified method of evaluating the potential for noise impact from transit projects), steps for evaluating noise impact with the General Noise Assessment procedure (a simplified assessment method to estimate noise impact and compare alternatives for transit projects), and steps for evaluating noise impact with the Detailed Noise Analysis procedure (a comprehensive assessment method to produce the most accurate estimates of noise impact intended for certain major public transportation projects).

Section 5: Transit Vibration — This section contains background information specific to transit vibration.

Section 6: Vibration Impact Analysis — This section provides a general outline of the entire vibration impact analysis process: guidelines on determining vibration impact criteria, methods for choosing the appropriate level of vibration analysis ("Screening," "General," or "Detailed"), steps for evaluating vibration impact with the vibration screening procedure (a simplified method of evaluating the potential for vibration impact from transit projects), steps for evaluating vibration impact with the general vibration assessment procedure (a simplified assessment method to estimate vibration impact and compare alternatives for transit projects), and steps for evaluating vibration impact with the detailed vibration analysis procedure (a comprehensive assessment method to produce the most accurate estimates of vibration impact intended for certain major public transportation projects).

Section 7: Noise and Vibration During Construction — This section presents the process of assessing noise and vibration impact during construction, including determination of level of assessment, source levels, impact criteria, and mitigation.

Section 8: Documentation of Noise and Vibration Assessment — This section includes guidance for documenting the noise and vibration assessment in technical reports and environmental documents.

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SECTION Project Class of Action and Planning
The level of environmental analysis and review depends on the significance of any potential associated environmental impacts, which in turn depends in part on the scope and complexity of the proposed project. The goals of a transit noise and vibration impact assessment are to:

I. Determine existing noise and vibration levels.

2. Assess project noise and vibration for potential impact.

3. Evaluate the effect of mitigation options on impacts.

The class of action determination will inform the required level of analysis. The FTA Regional office() determines the class of action based on project information provided by the project sponsor. The following types of information can assist the FTA Regional office in an initial class of action determination for a project:
• Project description
• Project -specific graphics, including:
• Project location/sizes
• Known land use and environmental features
• Additional information, as appropriate:
• Summary of prior planning
▪ Draft purpose and need statement
Project classes of action are described in Section 2.I. Project planning and development guidelines are presented in Section 2.2.

2. I Project Class of Action
FTA's environmental regulations classify projects by level of environmental analysis. The class of action will determine the appropriate level of analysis and documentation for a project. Details of each class are described in the following sections. For more information, review FTA's environmental impact and related procedures at 23 CFR part 771.

Environmental Impact Statements
Environmental impact statements (EISs) apply to projects that are expected to cause significant environmental effects in the NEPA context. Typical examples include new or extensions of fixed -guideway projects, such as heavy rail, light rail, commuter rail, and automated guideway transit (AGT) systems that are not located within existing transportation right-of-way (ROW). It is likely that for major infrastructure projects requiring an EIS, the most detailed treatment of noise and vibration impacts will often be required.

Categorical Exclusions
Categorical exclusions (CEs) cover actions that are excluded from requiring an EIS or environmental assessment (EA) because FTA has determined that they do http://www.fta.dot.gov/ 12926.html.

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not routinely cause significant environmental impacts. FTA's CEs are located at 23 CFR §§ 771.118(c) and (d), commonly referred to as the c -list and d -list, respectively. Examples of projects that would normally be CEs include vehicle purchases, maintenance of equipment, vehicles, or facilities, and ROW acquisition.

In general, CEs for transit capital construction projects often require at least a screening of noise impacts.

Environmental Assessments
When a proposed project is presented to FTA and it is uncertain whether the project requires an EIS or qualifies for a CE, FTA will normally direct the project sponsor to prepare an environmental assessment (EA) to assist in making the determination. An EA may be prepared for any type of project if uncertainty exists about the magnitude or extent of the impacts. Generally, an EA is selected over a CE if FTA determines that several types of potential impacts require further investigation, for example, air quality, noise, wetlands, historic sites, and/or traffic, but FTA's environmental regulation does not list typical projects that require EAs.

Experience shows that most of the EAs prepared for transit projects require at least a general assessment of noise impacts.

2.2 Project Planning and Development
Capital transit projects are ordinarily developed initially from a comprehensive transportation planning process conducted in metropolitan areas (see 23 CFR § 450.300).(4) The metropolitan planning process often includes some early consideration of social, economic, and environmental effects of proposed major infrastructure improvements. At this stage, environmental effects are usually considered on a broad scale —for example, overall development patterns, impacts on green space, and regional air quality. Noise and vibration assessments are not typically performed at this stage because the proposed infrastructure improvements lack the necessary detail.

Once the need for a capital transit project in a corridor is established in the metropolitan transportation plan, the transit mode and general alignment best suited for the corridor are identified. The Screening and General noise assessment procedures and the vibration screening procedure described in this manual may be used to compare noise and vibration effects among different transit modes and alignments at an early stage of the project planning. The analysis that results is documented through the environmental review process.

NEPA establishes a broad policy regarding mitigation as a means of accomplishing its environmental objectives. Other Federal laws, such as Section 4(f) (49 U.S.C. 303) and Section 404 (33 U.S.C. 1344), have explicit mitigation requirements for certain resources. The decision to include noise or vibration mitigation for a project is made by FTA and the project sponsor after public review of the environmental document, as appropriate. If mitigation measures are deemed necessary to protect the environment or to satisfy statutory requirements, they will be incorporated as an integral part of the project and subsequent grant documents will reference these measures as contractual obligations on the part of the project sponsor. Through that process, FTA FEDERAL TRANSIT ADMINISTRATION 4

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ensures that the project sponsor complies with all design and mitigation commitments contained in the environmental record.

Once the project enters construction, noise or vibration may need to be reassessed in some circumstances. Some large construction projects in densely populated residential areas may require noise monitoring to ensure agreed -upon noise limits are not exceeded. Vibration testing may be needed in the final stages of construction to determine whether vibration control measures have the predicted effect.

Considering that transit projects must be located amid or very close to concentrations of people, noise and vibration impacts can be a concern throughout the environmental review process, design, and construction phases.

This manual offers the flexibility to address noise and vibration at different stages in the development of a project and in different levels of detail.

2.3 Mitigation Policy Considerations
Because noise is frequently among the greatest environmental concerns of planned transit projects, FTA and the project sponsor should make reasonable efforts to reduce predicted noise to levels considered acceptable for affected noise -sensitive land uses. The need for noise mitigation is determined based on the magnitude of impact and consideration of factors specifically related to the proposed project and affected land uses.

The goal of providing noise mitigation is to gain substantial noise reduction, not simply to reduce the predicted levels to just below the "severe" impact threshold. For FTA to determine whether the mitigation is reasonable, the evaluation of specific mitigation measures should include the noise reduction potential, the cost, the effect on transit operations and maintenance, and any other relevant factors, such as any new environmental impacts that may be caused by the implementation of a noise reduction measure. A thorough evaluation enables FTA to make the findings required by NEPA and other statutes, such as Section 4(f) or Section 106 requirements and their implementing regulations.

Severe impacts have the greatest adverse impact on the community, and mitigation should be strongly considered. Areas with "moderate" impacts also have potential for effects on the community and therefore should also include consideration and possible adoption of mitigation measures when considered reasonable.

Since reasonableness is not strictly defined, FTA recommends that project sponsors work with the affected public and FTA staff during the environmental review process to decide appropriate mitigation strategies. A project sponsor may also consider developing and formally adopting a mitigation policy to aid in the determination of appropriate and applicable mitigation measures for current and proposed projects and anticipated impacts. Having such a policy in place can aid in the project planning up front and help to expedite mitigation decisions.

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The following considerations can assist in determining circumstances that trigger the need for mitigation and include examples of how they can be applied in a noise mitigation policy:
• Number of Noise -Sensitive Sites Affected
A row or cluster of residences adjacent to a rail transit line establishes a greater need for mitigation than one or several isolated residences in a mixed -use area. Single residences may not be able to meet a cost- effectiveness criterion for mitigation.

Example Mitigation Policy Consideration: Set a minimum number of noise -sensitive sites as a threshold, combined with a reference to a cost- effectiveness criterion.
• Increase over Existing Noise Levels
Since the noise impact criteria are delineated as bands or ranges, project noise can vary 5 to 7 decibels (dB) within the band of moderate impact at any specific ambient noise level. If the project and ambient noise plot falls just below the severe range, the need for mitigation is strongest for a moderate impact. Similarly, if the plot falls within the moderate range just above the no impact threshold, the impacts are expected to be less, so the justification for mitigation would not be as strong.

Example Mitigation Policy Consideration: Set a strong need for mitigation when a moderate impact is 2 dB (for example) over the no impact threshold.
• Noise Sensitivity of the Property
Section 4. I includes a comprehensive list of noise -sensitive land uses, yet there can be differences in noise sensitivity depending on individual circumstances. For example, parks and recreational areas vary in their sensitivity depending on the type of use they experience (active vs. passive recreation) and the settings in which they are located.

Example Mitigation Policy Consideration: Cite the use of the property as a determination of sensitivity for parks and recreational areas. • Effectiveness of the Mitigation Measure(s)
Determine the magnitude of the noise reduction that can be achieved, and consider whether there are conditions that limit effectiveness, such as noise barrier effectiveness for a multi -story apartment building.

Example Mitigation Policy Consideration: Set a minimum reduction in noise level to be considered effective. A 5 -dB reduction is typically considered an effective reduction from mitigation.
• Feasibility of the Mitigation Measure(s)
Determine if the mitigation measure is feasible from an engineering, operations or safety perspective. In some cases, it may not be possible to construct mitigation (noise barriers) due to physical or structural limitations FEDERAL TRANSIT ADMINISTRATION 6

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or because of safety concerns, especially related to sight lines for pedestrians and vehicles.

Example Mitigation Policy Consideration: State that the engineering design of the mitigation must be feasible, that it must be implementable in light of operations, and that mitigation must not compromise safety. ■ Fairness and Equity of the Mitigation Measure(s)
Ensure that mitigation measures are applied in a fair and equitable manner.

In many cases, small differences in distances or operations can result in small differences in projected noise levels. For example, all the residences in a row could have a projected moderate impact except for one residence at the end of the row that falls just under the moderate criteria due to being set slightly further back from the alignment. In a case like this, mitigation should be applied for the entire row of residences if possible.

Example Mitigation Policy Consideration: State that mitigation should be applied equitably.
• Existing Transportation Noise
Neighborhoods with ambient noise levels already heavily influenced by transportation noise, especially the same type of noise source as the project, should be considered. Often adding a new similar noise source will not add to the ambient noise levels or only slightly increase it to within acceptable levels. Whereas, impacts would be more likely, if the new noise was added to a neighborhood with minimal transportation noise. However, it is important to note that per (Section 4.1, Step 3) the higher the existing noise, the lower the allowable noise increase from new sources. A new cumulative noise environment may be very objectionable because people will not be compartmentalizing the existing noise versus the new noise and reacting only to the new noise. In this circumstance, impacts predicted in the moderate range could be treated as if they were severe.

Example Mitigation Policy Consideration: Set a policy that moderate impacts under these circumstances be treated as severe and cite the potential for reducing noise from existing transportation noise, as well as from project noise.
• Community Views
This manual provides the methodology to make an objective assessment of the need for noise mitigation. However, the views of the community should be considered where there are potential noise impacts predicted through this manual. The NEPA compliance process provides the framework for hearing the community's concerns about a proposed project and then making a good -faith effort to address those concerns. Many projects can be expected to have projected noise levels within the moderate impact range and, where possible, decisions regarding mitigation should be made after considering input from the affected public, relevant government agencies, and community organizations. There have been cases where the solution to the noise problem, a noise barrier, was not preferable to community members because of perceived adverse visual effects.

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Example Mitigation Policy Consideration: State that community input in determining the need for mitigation will be included whenever possible. ■ Implementation Cost
Cost is an important consideration in reaching decisions about noise mitigation measures. One guideline for gauging the reasonableness of the cost of mitigation is the state DOT's procedures on the subject. Many states have established their own cost threshold per benefited residence for determining whether installation of noise barriers for noise reduction is a reasonable expenditure. Several airport authorities have placed limits on the costs they will incur for sound insulation per residence for homes, and FTA assesses cost in a similar manner by benefited residence. Higher costs may be justified depending on the specific set of circumstances of a project.

Example Mitigation Policy Consideration: State the adopted cost threshold per benefited receiver for typical circumstances.

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SECTION Transit Noise
3 Source
This section presents the basic concepts of transit noise as background for computation methods and transit noise assessment procedures presented in Section 4. An overview of fundamental noise topics, including amplitude, frequency, time pattern, and decibel addition, is presented in Appendix B.

The Source -Path -Receiver framework for noise illustrated in Figure 3- I is central to all environmental noise studies. Each transit source generates noise that depends upon the type of source and its operating characteristics. Along the propagation path, between all sources and receivers, noise levels can be reduced (attenuated) by distance depending on ground type, intervening obstacles, and other factors. Finally, noise combines from multiple sources at each receiver and potentially interferes with activities at that location.

Path Receiver
This section contains the following:

Figure 3-I Source -Path -Receiver Framework
■ Section 3. I presents the noise metrics used in this manual. • Section 3.2 provides an overview of transit noise sources, including a listing of major sources and a discussion of noise -generation mechanisms.
• Section 3.3 provides an overview of noise paths, including a discussion of the various attenuating mechanisms on the path between source and receiver.
• Section 3.4 provides an overview of receiver response to transit noise, including a discussion of the technical background for transit noise criteria and the distinction between absolute and relative noise impact.

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3.1 Noise Metrics
This manual uses the noise metrics outlined in Table 3-1 for transit noise measurements, computations, and assessment. The terminology is consistent with common usage in the United States. All of these noise metrics are expressed in units of A -weighted decibels (dBA). A -weighted sound levels represent the overall noise at a receiver that is adjusted in frequency to approximate typical human hearing sensitivity. This is the basic noise unit for transit noise analyses.

Table 3- I Noise Metrics
Metric
Abbreviation
Definition
A -weighted Sound Level
dBA
A -weighted sound levels represent the overall noise at a receiver that is adjusted in frequency to approximate typical human hearing sensitivity. This is expressed as A -weighted decibels (dBA), the basic noise unit for transit noise analyses.

Sound Exposure Level
SEL
SEL is the cumulative noise exposure from a single noise event, normalized to one second. SEL contains the same overall sound energy as the actual varying sound energy during the event. It is the primary metric for the measurement of transit vehicle noise emissions, and is an intermediate metric in the measurement and calculation of both Le((t) and Ldn.

Equivalent Sound Level
Leq(t)
The equivalent sound level Leq(t) describes a receiver's cumulative noise exposure from all events normalized to a specified period of time "t". Leq(t) represents a hypothetical, constant sound level and contains the same overall sound energy as the actual varying sound energy during the time period "t". For transit noise impact assessments, the equivalent sound level metric is A -weighted and all events are normalized over a one -hour time period, Leq(Ihr)• For transit noise assessments, this metric is appropriate for non-residential land uses and is computed for the loudest hour of project related activity during hours of noise sensitivity.

Day -Night Sound Level
Ldn
Ldn describes a receiver's cumulative noise exposure from all events over 24 hours. Events between 10 p.m. and 7 a.m. are increased by 10 dB to account for humans' greater nighttime sensitivity to noise. Ldn is used to assess transit noise for residential land uses.

Maximum Sound Level
Lax
The maximum level describes the maximum noise level reached during a single noise event. For transit noise impact assessments, it is appropriate to consider the A -weighted maximum level (Lmax ) to understand the full context of the scenario. It is not appropriate to use this metric for transit noise impact assessments. This metric is commonly used in vehicle noise specifications and commonly measured for individual vehicles.

The noise metrics, including their application to transit noise and vibration impact assessment, are described in more detail in Appendix B.I.4. Mathematical definitions and graphic illustrations are presented to facilitate understanding and the interrelationships among metrics.

3.2 Sources of Transit Vehicle Noise
This section discusses major characteristics of the sources of transit noise.

Transit noise can be generated by transit vehicles in motion, stationary transit FEDERAL TRANSIT ADMINISTRATION 10

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vehicles, and fixed -transit facilities. Procedures for computing nearby noise levels for major sources as a function of operating parameters such as vehicle speed are given in Sections 4.4 and 4.5.

Transit Vehicles in Motion
Transit vehicles most noticeably create noise when in motion. Noise from transit vehicles in motion can come from multiple sources, including the propulsion unit (i.e., the engine and engine components), the interaction of the wheels and/or tires and the running surface, and warning bells and horns.

Vehicle propulsion units generate:
• Whine from electric control systems and traction motors that propel rapid transit cars
• Diesel -engine exhaust noise from both diesel-electric locomotives and transit buses
• Air -turbulence noise generated by cooling fans
• Gear noise
Noise is also generated by the interaction of wheels and/or tires with their running surfaces. Tire noise from rubber -tired vehicles is generated at normal operating speeds. The interaction of steel wheels and rails generates:
• Rolling noise due to continuous rolling contact
• Impact noise when a wheel encounters a discontinuity in the running surface such as a rail joint, turnout or crossover (where the train or rail vehicle switches off one track and onto another)
• Impact noise from the wheel and running surface if the wheel is not completely round (wheel flat) or if the running surface is not completely flat
• Squeal generated by friction between wheels and rail on tight curves Transit vehicles are equipped with horns and bells for use in emergency situations and as a general audible warning to track workers and trespassers within the ROW, pedestrians, and motor vehicles at highway grade crossings.

Horns and bells on the moving transit vehicle combined with stationary bells at - grade crossings can generate high noise levels for nearby residents and are often sources of complaints.

For many noise sources, such as transit vehicles, the sound level is dependent on the speed of the noise source. In other cases, such as for stationary sources or horns mounted on vehicles, the sound level is not dependent on speed.

Figure 3-2 illustrates sound level dependence on speed for a diesel -powered commuter rail train and an electric -powered transit train assuming all other parameters, such as weight, are equal. Plotted vertically in this figure is a notional indication of the maximum sound level during a passby. Speed dependence is strong for electric -powered transit trains because wheel/rail noise is the dominant noise source and noise from this type of source increases strongly with speed. Diesel -powered commuter rail train noise is dominated by the locomotive exhaust noise at slower speeds. As speed increases, wheel -rail

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noise becomes the dominant noise source and diesel- and electric -powered trains generate similar noise levels. Similarly, speed dependence is also strong for automobiles, city buses (two -axle), and non -accelerating highway buses (three -axle), because tire/pavement noise is the dominant noise source for these vehicles. Accelerating highway bus noise is dominated by exhaust noise.

Sound Level
oWeted
0\e90P mute( �a�1
Gon - -
Train Speed
Figure 3-2 Sound Level Dependence on Speed
Sound levels close to the source are also dependent on vehicle acceleration, vehicle length, running surface type, and running surface condition. For high- speed rail vehicles (vehicles with an operating speed of 90-250 mph are typically beyond the scope of this manual), air turbulence can also be a source of noise.

In addition, for an elevated structure, the guideway can radiate noise as it vibrates in response to the dynamic loading of the moving vehicle.

Stationary Transit Vehicles
Noise can be generated by transit vehicles even when they are stationary. For example, auxiliary equipment such as cooling fans on motors, radiator fans, plus hydraulic, pneumatic, and air-conditioning pumps, often continue to run when vehicles are stationary. Transit buses are also often left idling in stations or storage yards.

Fixed -transit Facilities
Noise can also be generated by sources at fixed -transit facilities. Such sources include ventilation fans in transit stations, subway tunnels, and electric power substations, as well as equipment in chiller plants, and many activities within maintenance facilities and shops.

Common Noise Sources
Table 3-2 summarizes common sources of transit noise by vehicle and facility type.

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Table 3-2 Sources of Transit Noise
Vehicle or Facility*
Dominant Components
Comments
RRT or Light Rail Transit
(LRT) on exclusive ROW
Wheel/rail interaction and
guideway amplification
Depends on condition of wheels and rails
Propulsion system
When accelerating and at higher speeds
Brakes
When stopping
Auxiliary equipment
When stopped
Wheel squeal
On tight curves
In general
Noise increases with speed and train length
LRT in Mixed Traffic
Wheel squeal
On tight curves
Auxiliary equipment
When stopped
Horns and crossing bells
At -grade crossings and stations
In general
Traveling at lower speeds in mixed traffic
produces less noise than when traveling at
higher speeds in exclusive ROW
Commuter Rail
Diesel exhaust
On diesel -hauled trains
Cooling fans
On both diesel and electric -powered trains
Wheel/rail interaction
Depends on condition of wheels and rails
Horns and crossing gate bells
At -grade crossings and stations
In general
Noise is usually dominated by locomotives and
horns/bells at -grade crossings
Low and Intermediate
Capacity Transit
Propulsion systems, including
speed controllers
At low speeds
Ventilation systems
At low speeds
Tire/guideway interaction
For rubber -tired vehicles, including monorails
Wheel/rail interaction
Depends on condition of wheels and rails
In general
Wide range of vehicles: monorail, rubber -
tired, steel -wheeled, linear induction. Noise
characteristics depend upon type
Diesel Buses
Cooling fans
While idling
Engine casing
While idling
Diesel exhaust
At low speeds and while accelerating
Tire/roadway interaction
At moderate and high speeds
In general
Includes city buses (generally two -axle) and
commuter buses (generally three -axle)
Electric Buses and
Trackless Trolleys
Tire/roadway interaction
At moderate speeds
Electric traction motors
At moderate speeds
In general
Much quieter than diesel buses
Bus Storage Yards
Buses starting up
Usually most disruptive in the early morning
Buses accelerating
Usually near entrances/exits and/or locations
that require buses to accelerate (tight turns)
Buses idling Warm-up areas
In general Site specific: often peak periods with
considerable noise
Rail Transit Storage Yards
Wheel squeal On tight curves
Wheel impacts On joints and switches
Wheel rolling noise On tangent track
Auxiliary equipment Throughout clay and night; includes air -break release noise
Coupling/uncoupling On storage tracks
Signal horns Throughout yard site
In general
Site specific: often early morning and peak
periods with considerable noise
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Maintenance Facilities
Signal horns
Throughout facility
Intercoms
Throughout facility
Impact tools
Shop buildings
Car/bus washers/driers
Wash facility
Vehicle activity
Throughout facility
In general
Site specific: considerable activity throughout
day and night, some outside.

Stations
Automobiles
Patron arrival/departure, especially in early
morning
Buses idling
Bus loading zone
Intercoms
Platform area
Locomotive idling
At commuter rail terminal stations
Auxiliary systems
At terminal stations and layover facilities
Horns
At stations, if applicable
In general
Site specific, with peak activity periods
Subways
Fans
Noise through vent shafts/structures
Buses/trains in tunnels
Noise through vent shafts/structures
In general
Noise is not a problem, except in the
immediate vicinity of vent shafts/structures.
* Refer to Appendix A for additional information.

3.3 Paths of Transit Noise from Source to
Receiver
This section contains a qualitative overview of noise -path characteristics from source to receiver, including attenuation along these paths. Equations for specific noise -level attenuations along source -receiver paths are included in Sections 4.4 and 4.5.

Sound paths from source to receiver are predominantly through the air. Along these paths, sound reduces with distance due to divergence, absorption/diffusion, and shielding. These mechanisms of sound attenuation are discussed below.

Divergence
Sound levels naturally attenuate with distance, as shown in Figure 3-3. The plot shows attenuation at the receiver relative to the sound level 50 ft from the source. This type of attenuation is called divergence and is dependent upon source configuration (line or point source) or other source -emission characteristics. Localized sources (point sources) grouped closely together attenuate greatly with distance at a rate of approximately 6 dB per doubling of distance. Examples of point sources include highway grade -crossing signals along rail corridors, intercoms in maintenance yards and other closely grouped sources of noise. Vehicles passing along a track or roadway forming a line are called line sources. Line sources attenuate less than point sources with distance.

Rate of attenuation for line sources varies depending on the noise metric. Leq(Ihr) and Ldn noise levels attenuate at a rate of 3 dB per doubling of distance and Lmax noise levels attenuate at a rate of 3 to 6 dBs per doubling of distance.

Figure 3-3 illustrates approximate attenuation with distance between the source and receiver for point and line sources. The Tine source curve for the Lmax noise FEDERAL TRANSIT ADMINISTRATION 14

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metric separates into three curves because it is dependent on the length of the line source. Equations for the curves in Figure 3-3 are included in Section 4.5.

Attenuation, d6
0 10
20 30
40 50 100 500
Source -receiver distance, in feel
1,000
Figure 3-3 Attenuation Due to Distance (Divergence)
Absorption/Diffusion
In addition to distance, sound levels can be attenuated depending on the type of ground between the source and receiver. A portion of the sound energy is absorbed by the ground and only the remaining energy travels to the source.

How much energy the ground absorbs is dependent on the ground type (characterized as acoustically "hard" or "soft") and geometry. Example absorptive ground types include freshly -plowed or vegetation -covered ground.

Figure 3-4 illustrates approximate attenuation due to ground type by source to receiver path distance and height. Ground attenuation can be as large as 5 dB over a path distance of several hundred ft. At very large distances, wind and temperature gradients could modify the expected ground attenuation. However, these variable atmospheric effects are not included in this manual because they generally occur beyond the range of typical transit -noise impact. Equations for the curves in this figure are included in Section 4.5.
m
c
o
c
c
m
100
40ft
30ft
20 ft
10 ft
5 ft or less
Average path height above absorptive ground IL
500
Source -receiver distance, in feet
1,000
Figure 3-4 Attenuation due to Soft Ground
Shielding
Sound paths are sometimes interrupted by terrain, human -constructed noise barriers, rows of buildings, or other objects. Noise barriers are one of the most effective means of mitigating noise (Section 4.5, Step 7). A noise barrier reduces sound levels at a receiver by breaking the direct line -of -sight between source and receiver with a solid wall (in contrast to vegetation which hides the source from view but does not reduce sound levels substantially over short distances).

Sound energy reaches the receiver only by bending (diffracting) over the top of FEDERAL TRANSIT ADMINISTRATION 15

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the barrier, as shown in Figure 3-5. This diffraction over the barrier reduces the sound level that reaches the receiver. One important consideration in using noise barriers to mitigate noise impacts is safety. Noise barriers, if not designed and sited carefully, can reduce visibility of trains for pedestrians and motorists, leading to less safe conditions. It is important to consult with safety experts when choosing and siting a noise barrier.

Noise barriers for transportation systems are typically used to attenuate noise at the receiver, potentially reducing received sound levels by 5 to 15 dB, depending upon barrier height, length, and distance from both source and receiver. Barriers on structures close to the transportation noise source may provide less attenuation than barriers located farther from the source due to reverberation (multiple reflections) between the barrier and the body of the vehicle or noise source. This reverberation can be offset by increased barrier height and/or acoustical absorption on the source side of the barrier. Further discussion and equations on acoustical absorption and barrier attenuation is provided in Section 4.5.

Source -to -receiver sound paths may not always travel through the air, but rather through the ground or through structural components of the receiver's building. Discussion of such ground -borne and structure -borne propagation is included in Section 5.

Rail car
Barrier ]
L Barrier
without absorption
Sound
Shadow
o
o
L Barrier
with absorption
Figure 3-5 Noise Barrier Geometry

3.4 Receiver Response to Transit Noise
This section contains an overview of human receiver response to noise. It serves as background information for the noise impact criteria in Section 4. I .

Noise can interrupt ongoing activities causing community annoyance, especially in residential areas. In general, most residents become highly annoyed when noise interferes considerably with activities such as sleeping, talking, noise - sensitive work, and audio entertainment. In addition, some land uses, such as outdoor concert pavilions, are inherently incompatible with high noise levels.

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Annoyance from noise has been investigated and approximate dose -response relationships have been quantified by the U.S. Environmental Protection Agency (EPA).(5) The selection of noise metrics in this manual is largely based upon this EPA work. Beginning in the 1970s, the EPA undertook a number of research and synthesis studies relating to community noise of all types. Results of these studies have been widely published, discussed, and refereed by many professionals in acoustics. Basic conclusions of these studies have been adopted by the Federal Interagency Committee on Noise (FICON),(ii) the U.S.

Department of Housing and Urban Development (HUD), the American National Standards Institute, and even internationally(6)(7)(8)(9) Conclusions from this seminal EPA work remain scientifically relevant today.

Figure 3-6 contains a synthesis of actual case studies of community reaction to newly introduced sources of noise in a residential urban neighborhood.('°) Plotted horizontally in the figure is the increase in noise from new sources above existing noise levels expressed as Day -Night Sound Levels, Ldri, discussed in Appendix B. I.4.5. Plotted vertically is the community reaction to this newly introduced noise. As shown in the figure, community reaction varies from no reaction to vigorous action for newly introduced noises averaging from I 0 dB below existing to 25 dB above existing. Note the assumptions included in the graphic are associated with the specific data points from the study. These assumptions are generally appropriate to give context to most transit projects, but community reaction may differ for conditions specific to each project.

In many community attitudinal surveys, transportation noise has been ranked among the greatest causes of community dissatisfaction. A synthesis of many such surveys on annoyance is shown in Figure 3-7.(0 x)(12) Noise exposure levels are plotted against the percentage of people who are highly annoyed by the particular level of neighborhood noise. As shown in the figure, the percentage of high annoyance is approximately 0 percent at 45 dB, I 0 percent around 60 dB, and increases quite rapidly to approximately 70 percent around 85 dB. The scatter about the synthesis line is due to community variation and wording differences in the surveys. An update of the original research containing additional railroad, transit and street traffic noise surveys generally follows the shape of the original response curve shown in Figure 3-7.(12)(13) As indicated by Figure 3-6 and Figure 3-7, introduction of certain levels of transit noise into a community may have two undesirable effects. First, it may substantially increase noise levels above existing noise levels in a community.

This effect is called a relative noise impact. Evaluation of this effect compares new noise levels to the existing levels. Criteria for a relative noise impact evaluation are based upon noise increases above existing levels. Second, newly introduced transit noise may interfere with community activities independent of existing noise levels. For example, it may be too loud to converse or sleep. This effect is called absolute noise impact and is expressed as a fixed level threshold that is not to be exceeded. The fixed level threshold is determined independently of existing noise levels. Relative and absolute noise impacts are discussed in terms of transit noise criteria in Section 4.I, Step 3.

The Federal Interagency Committee on Aviation Noise (FICAN) is the current version of this group.

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Community Reaction
Vigorous Action
Several threats
of legal action
or strong appeals
to local officials
to stop noise
Widespread complaints
or single threat
of legal action
Sporadic complaints
No reaction
although noise is
generally noticeable
Percentage of people highly annoyed
100
90 0
70 60
50 40
30 D▪ M • OM IMMO
■ ■ ■
• ■ • ■■■
U. •
■ ■
■■■■■■■■
■■ ■ ■
Assumptions
Some prior exposure.

Windows partially open.

No pure tones or impulses.
-20 -10 0 10 20
Increase in noise from new sources above existings noise levels, Ldn Figure 3-6 Community Reaction to New Noise, Relative to Existing Noise in a Residential Urban Environment
50 60 70
Day -Night Sound Level, Ldn
80 90
Figure 3-7 Community Annoyance Due to Noise
30 FEDERAL TRANSIT ADMINISTRATION 18

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SECTION Noise Impact Analysis
4 The FTA noise impact analysis process is a multi -step process used to evaluate the project for potential noise impacts for FTA NEPA approvals. If impact is determined, measures necessary to mitigate adverse impacts must be considered for incorporation into the project.(4) It is recommended that project sponsors develop and formally adopt a policy for determining the need for mitigation for situations that are loosely covered by the impact criteria.

Considerations for mitigation policies are included in Section 2.3. The FTA noise impact analysis steps are summarized as follows and are described in the subsequent subsections:

4.1: Determine noise impact criteria.

Step I: Identify the type of project/dominant noise source (transit or multimodal).

Step 2: Choose land use category for FTA criteria.

4.2: Determine the highest appropriate level of noise analysis for the current stage of project planning or development.

4.3: Evaluate for the potential of impact according to the Noise Screening Procedure.

Step 1: Identify project type.

Step 2: Determine the screening distance.

Step 3: Identify the study area.

Step 4: Locate noise -sensitive land uses.

4.4: Evaluate impact according to the General Noise Assessment and evaluate preliminary mitigation options if impact is found.

Step I: Identify noise -sensitive receivers.

Step 2: Determine the project noise source reference levels.

Step 3: Estimate project noise exposure by distance.

Step 4: Combine noise exposure from all sources.

Step 5: Measure existing noise exposure.

Step 6: Inventory noise impacts.

Step 7: Determine noise mitigation needs.

4.5: Evaluate for impact according to the Detailed Noise Analysis and evaluate mitigation options if impact is found.

Step I: Identify noise -sensitive receivers.

Step 2: Determine noise source levels for detailed analysis.

Step 3: Calculate project noise exposure by distance.

Step 4: Combine noise exposure from all sources.

Step 5: Determine existing noise exposure.

Step 6: Assess noise impact.

Step 7: Determine noise mitigation measures.

In addition to analyzing for potential noise impacts, analyze the project for potential vibration impacts according to the process presented in Section 6.

After both the noise and vibration analyses have been completed, assess FEDERAL TRANSIT ADMINISTRATION 19

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construction noise and vibration according to Section 7 and document findings according to Section 8.

4. I Determine Noise Impact Criteria
This section describes the procedure for determining the appropriate criteria for assessing project noise impact based on the type of project and project noise source. Project noise is the new noise or change in noise introduced by the project. Noise impact criteria may vary for different segments of the project. Project segments can be portions of a project with similar characteristics.

The procedure to determine the appropriate impact criteria is described in this section and shown more simply as a flow chart in Figure 4-1. If there is uncertainty in how to determine the appropriate criteria, contact the FTA Regional office.

The selected criteria are used in the analysis procedures discussed in Sections

4.3, 4.4, and 4.5 to identify potential impacts and the level of impact.

Start
Yes/ Transit N\NQ
only?
V
Transit
Project
FTA criteria
& methods

FTA & FHWA
criteria & methods
yi
(._
M ulti-modal
Project /
Transit
wU sources dominate
at all times?
Highway N\
sources dominate
atall times?%
f FHWA criteria
& methods
Yes
Yes
Figure 4-I Noise Impact Criteria Flow Chart by Project Segment FEDERAL TRANSIT ADMINISTRATION 20

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Step I: Identify Project Type
Identify the type of project as transit, multimodal (transit and highway), or other multimodal according to the dominant noise source.

Option A: Transit Project (Transit Noise Only) — The transit project category includes all transit projects where the project noise is exclusively due to new transit sources, no changes are made to the highway or to existing highway noise barriers, and the existing noise levels generated by roadway sources will not change because of the project. For these transit projects, FTA is the lead agency conducting the environmental review in cooperation with the transit agency.

Typical examples of transit projects include:
■ RRT, LRT, commuter rail, and AGT
■ Rail projects built within an existing highway or railroad corridor that do not alter the existing noise levels generated by roadway sources ■ Bus facility projects with operations on local streets and highways used to access the facility, where the project does not include roadway construction or modification that changes roadway capacity substantially ■ Fixed facilities including storage and maintenance yards, passenger stations and terminals, parking facilities, and substations ■ Portions of transit projects not adjacent to highway corridors FTA impact criteria are appropriate for transit projects, proceed to Step 2.

Option B: Multimodal Project (Transit and Highway Noise) — In this manual, "multimodal" refers to projects that include changes to both transit and highway components, resulting in project noise comprised of both highway and transit noise sources.

Typical examples of multimodal projects include:
■ New highway construction providing general-purpose lanes as well as dedicated bus and high occupancy vehicle (HOV) lanes
■ Rail transit projects that involve changes to the highway travel lanes or existing highway noise barriers
Evaluate multimodal projects for impact according to the project noise source by project segment. FHWA's noise assessment methods are used to inform FTA's NEPA evaluation only for segments where highway noise levels change due to the transit project. These projects are not necessarily subject to FHWA's procedures at 23 CFR part 772 (see call out box below). For segments of the project outside the highway corridor, use FTA's criteria and methods. Use Table 4- I to determine multimodal project noise.

Once the project noise source(s) is identified, determine the appropriate assessment method according to Table 4-2.

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Note that a separate noise analysis may be required for FHWA approval of a multimodal project pursuant to 23 CFR part 772. For these projects, it is important to work with FHWA early in the environmental review process to determine how a noise assessment will be completed where FHWA approval is needed for the project.

The determination of whether a project is subject to FHWA procedures at 23 CFR part 772 depends upon the specific circumstances of a project. A proposed transit project that would share an existing highway ROW is not necessarily a FHWA-defined multimodal project. A transit project that meets all three of the following criteria is not considered a multimodal project subject to 23 CFR part 772:
■ FTA is the lead agency in the NEPA process and FHWA's limited participation is as a cooperating agency.
• The main transportation purpose of the project, as stated in the purpose and need statement of the environmental document, is transit -related and not highway -related. ■ No Federal -aid highway funds are being used to fund the project.

Table 4-I Multimodal Project Noise Factors
Factor
Description
Volume of
Traffic
Major freeways and interstate highways often carry large volumes of traffic throughout the day and night such that the highway noise dominates at all times. Transit noise in this case may be unimportant by comparison, but must still be evaluated using FTA's noise criteria for a potential impact.

Traffic Patterns
Some highways and arterials serve primarily as commuter routes such that nighttime traffic diminishes considerably, while transit systems continue to operate well into the late hours. Here the dominant noise source at times of maximum sensitivity may be transit.

Type of Traffic
Some highways and arterials may serve commuters during the daytime hours, but provide access to business centers by trucks at night. In this case, the roadway noise would likely continue to dominate.

Alignment
Configuration
Elevation of the transit mode in the median or beside a busy highway may result in transit noise contributing more noise to nearby neighborhoods than a highway that may be partially shielded by rows of buildings adjacent to the ROW. In this case, both transit and highway noise may be considered dominant.

Table 4-2 Multimodal Project Assessment Methods
Dominant
Noise Source
Assessment Method
Transit, at
All Times
Use FTA criteria and methods. Proceed to Step 2.

Highway, at
All Times
Use FHWA criteria and methods to inform FTA's NEPA evaluation. Contact FHWA directly for assistance using FHWA noise analysis methods and FHWA noise impact criteria.

Transit and
Highway at
Different Times
Use both the FHWA and FTA methods to determine if one, both, or neither method determines impact due to the project noise for these segments. Note that the project noise includes both highway and transit sources associated with the project. Both methods are used because the FTA methods consider nighttime sensitivity while the FHWA methods consider the peak traffic hour.

Proceed to Step 2 for FTA criteria. Contact FHWA directly for assistance using FHWA noise analysis methods and FHWA noise impact criteria.

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Option C: Other Multimodal Projects — For projects with components from other modes, contact the FTA Regional office. Additional information on high-speed rail vibration and noise can be found in the Federal Railroad Administration (FRA) "High -Speed Ground Transportation Noise and Vibration Impact Assessment" guidance manual.(14)
Step 2: Choose Land Use Category for FTA Criteria
Determine the appropriate noise -sensitive land use category for the project segment using Table 4-3 and the descriptions below then, proceed to Step 3. FTA criteria are presented by land use.

Table 4-3 Land Use Categories and Metrics for Transit Noise Impact Criteria Land Use
Category
Land Use
Type
Noise
Metric, dBA
Description of Land Use Category
High
Sensitivity
Outdoor
Leq(Ihr)*
Land where quiet is an essential element of its intended purpose. Example land uses include preserved land for
serenity and quiet, outdoor amphitheaters and concert
pavilions, and national historic landmarks with
considerable outdoor use. Recording studios and concert halls are also included in this category.
2 Residential
Outdoor Lan
This category is applicable all residential land use and buildings where people normally sleep, such as hotels and hospitals.
3 Institutional
Outdoor
Leq(Ihr)*
This category is applicable to institutional land uses with primarily daytime and evening use. Example land uses
include schools, libraries, theaters, and churches where it is important to avoid interference with such activities as speech, meditation, and concentration on reading
material. Places for meditation or study associated with cemeteries, monuments, museums, campgrounds, and
recreational facilities are also included in this category. * Leq(Ihr) for the loudest hour of project -related activity during hours of noise sensitivity.

Noise -sensitive land use categories are described in in order of sensitivity. Most commercial or industrial uses are not considered noise -sensitive because activities within these buildings are generally compatible with higher noise levels.

Business can be considered noise -sensitive if low noise levels are an important part of operations, such as sound and motion picture recording studios.

For residential land use (category 2), apply the noise criteria at the nearest facade of the occupied portion of the building, e.g., not at a garage or porch.

The residential criteria should be applied at locations with nighttime sensitivity.

For major noise -sensitive outdoor use at non-residential locations, apply the noise criteria at the point of noise -sensitive use nearest the noise source.

Land use categories are evaluated using noise metrics that reflect the noise - sensitive time of day:
• Categories I and 3 — The noise metric, Leq(Ihr) is used for all category I and 3 land uses where nighttime sensitivity is not a factor. Category 3 land uses are considered less noise -sensitive than category I land uses.

For transit analyses, Leq(Ihr) is computed for the noisiest hour of transit - FEDERAL TRANSIT ADMINISTRATION 23

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related activity during which human activities occur at the noise - sensitive location. See Appendix B. I.4.4 for more information on this metric.
• Category 2 — The noise metric Lan is a used for all category 2 land uses where nighttime sensitivity is a factor. This noise metric includes a I0 - dB penalty for nighttime noise. See Appendix B.I.4.5 for more information on this metric.

Land Use Categories: Special Cases
Historic sites, parks, indoor -only land use, and undeveloped land require special consideration. In addition to NEPA, noise impacts may need to be considered under other environmental laws such as Section 106(15) or Section 4(f).(16) Indoor -only use and undeveloped land should be evaluated on a case -by -case basis to determine noise sensitivity based on how each facility is used or the reason it is protected under the applicable requirement.

Historic Sites — Section 106 requires Federal agencies to evaluate potential effects from projects on historic properties. Per the regulations at 36 CFR part 800=07) historic properties are defined as any prehistoric or historic district, site, building, structure, or object included in, or eligible for the National Register of Historic Places (NRHP). An adverse effect determination under Section 106 is made when a project may alter, directly or indirectly, any of the characteristics of a historic property that qualify the property for inclusion in the National Register in a manner that would diminish the integrity of the property's location, design, setting, materials, workmanship, feeling, or association.

Under FTA environmental reviews, some structures may be evaluated as noise - sensitive resources per this noise manual and evaluated as historic properties under Section 106. However, because this manual and Section 106 regulations have different criteria for effect, identifying a severe noise impact for a structure under this manual does not necessarily mean there would be an adverse effect under Section 106. It is important to thoroughly document the characteristics of historic properties that qualify for inclusion in the NRHP for evaluation of effect under Section I06.

If a property, for example, is listed on the NRHP under criterion C because the structure possesses high artistic values, but lacks integrity of setting, feeling, or association, it is unlikely that a change in the noise environment would affect the features that qualify the property for listing or eligibility for inclusion in the NRHP.

In the assessment of effects on historic properties, consideration should be given to not just the proposed transit project, but any associated mitigation measures with the transit project. For example, if a transit project would involve noise walls or berms as mitigation, the effect of those structures on the visual setting may need to be considered in a Section 106 analysis.

Parks — Most parks used primarily for active recreation such as sports complexes and bike or running paths are not considered noise -sensitive.

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However, some parks (even some in dense urban areas) are primarily used for passive recreation such as reading, conversation, or meditation. These places, which may be valued as havens from the noise and rapid pace of everyday city life, are treated as noise -sensitive, and are included in land use category 3.

Consult the state or local agency with jurisdiction over the park on questions about how the park is used, and visit the park to observe its use, if possible.

Indoor -Only Use — The land use categories described in this section correspond with noise impact criteria that provide protection for both outdoor and indoor land uses. For locations where noise impact will be evaluated but there is no outdoor land use such as apartment buildings, hotels or upper levels of multi -story buildings, indoor criteria can be used. In these cases, the criterion for indoor noise levels from project sources is a Ldn of 45 dBA.(18) This criterion is consistent with the Federal Aviation Administration (FAA). See Section 4.5 for more information on how indoor criteria apply to noise mitigation consideration.

Undeveloped Land — Undeveloped land may also need to be considered for noise impact assessment and mitigation if plans are under way to develop the land for noise -sensitive use. The policy for considering such land for assessment and mitigation should be determined on a project -specific basis by the project sponsor in consultation with the FTA Regional office.

Step 3: Determine Appropriate FTA Criteria Presentation FTA criteria for noise impact were developed specifically for transit noise sources operating on fixed -guideways or at fixed facilities in urban areas. These criteria are based on well -documented research on human response to community noise and represent a reasonable balance between community benefit and project costs. These criteria do not reflect specific community attitudinal factors. See Appendix C for additional background information on the development of FTA noise criteria.

The criteria specify a comparison of future project noise with existing noise.

Note that projections of future noise exposure without the project (no -build scenario) are not included in this analysis. The criteria also consider land use which is an important factor that reflects noise sensitivity based on activity and time period of concern. The criteria are defined with the expectation that communities already exposed to high levels of noise can only tolerate a small increase. In contrast, if the existing noise levels are low, it is reasonable to allow a greater change in the community noise.

The levels of impact are described in Table 4-4. The criteria at which the levels of impact occur are presented in two ways depending on the relationship of project and existing noise sources.

If the project noise source is a new source of transit noise in the community, such as a new project in an area currently without transit, use the criteria as presented in Option A. if the project noise adds to or changes existing transit noise in the community, use the criteria as presented in Option B.

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Table 4-4 Levels of Impact
Level of Impact
Description
No Impact
Project -generated noise is not likely to cause community annoyance. Noise projections in this range are considered acceptable by FTA and mitigation is not required.

Moderate Impact
Project -generated noise in this range is considered to cause impact at the threshold of measurable annoyance. Moderate impacts serve as an alert to project planners for potential adverse impacts and complaints from the community. Mitigation should be considered at this level of impact based on project specifics and details concerning the affected properties.

Severe Impact
Project -generated noise in this range is likely to cause a high level of community annoyance. The project sponsor should first evaluate alternative locations/alignments to determine whether it is feasible to avoid severe impacts altogether. In densely populated urban areas, evaluation of alternative locations may reveal a trade-off of affected groups, particularly for surface rail alignments. Projects that are characterized as point sources rather than line sources often present greater opportunity for selecting alternative sites. This guidance manual and FTA's environmental impact regulations both encourage project sites which are compatible with surrounding development when possible. If it is not practical to avoid severe impacts by changing the location of the project, mitigation measures must be considered.

Option A: Project Noise Impact Criteria Presentation — The impact criteria presentation for evaluating existing noise independently to project noise is presented in this option.

The noise levels at which impacts occur are presented in Figure 4-2 and Table 4-5. Equations for the impact criteria are presented in Appendix C. If impact is determined, measures necessary to mitigate impacts are to be considered for incorporation into the project.(3)
Figure 4-2 presents the existing noise exposure on the horizontal axis and project noise on the vertical axis. Category I and 2 land uses have the same criteria for project noise and are on the primary vertical axis. Category 3 land use criteria are presented on the secondary vertical axis. Note that project noise for category I and 3 land uses is expressed as Limo, whereas project noise for category 2 land use is expressed as Ldn. Also, note that project noise criteria are 5 dB higher for category 3 land uses in Figure 4-2 since these types of land use are less noise -sensitive than those in categories I and 2.

Note that for projects in locations with existing noise levels below 55 dBA, the project noise exposure is allowed some increase over the existing noise exposure before it is considered to cause impact. For category I and 2 land uses, the maximum project noise level to be considered to cause no impact is 65 dBA (Leq(Ihr) or Ldn) regardless of the existing noise. Note that no impact at 65 dBA aligns with other Federal agencies in that a Ldn of 65 dBA is a standard limit for an acceptable living environment among some Federal agencies.(19) (20) Project noise levels above the top curve are considered to cause severe impact.

The upper limit of the severe impact range is 75 dBA for category I and 2 land uses. The upper limit of 75 dBA is associated with an unacceptable living environment. Project noise between the two curves is considered to have moderate impact on the community.

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The criteria are also tabulated in Table 4-5. Figure 4-2 and the equations that correspond with this figure in Appendix C are the precise definition of the criteria. The values in Table 4-5 can be used for illustrative purposes and should only be used if all numbers are rounded up to the nearest decibel. 80 75
Q 70
OD.
`• 6c 65
0 •
x '`
LLJ
a) &60
y
Q f
z U U
U 55
N N
0_
50 45
40 75
40 45 50 55 60 65 70
Existing Noise Exposure (d8A)
45 80
85 80
75 70
65 60
55 50
Figure 4-2 Noise Impact Criteria for Transit Projects
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Table 4-5 Noise Levels Defining Impact for Transit Projects Existing
Noise
Exposure,
dBA
Project
Noise Impact Exposure, dBA
Category l (Leq(Ihr)) or 2 (Lan) Sites
Category 3 Sites (Leq(Ihr))
Leq(Ihr) or Ldn
No
Impact
Moderate
Impact
Severe
Impact
No
Impact
Moderate
Impact
Severe
Impact

Ambient+I5

Ambient+20
43 58
63 44
58 63
45 58
63 46
59 64
47 59
64 48
59 64
49 59
64 50
59 64
51 60
65 52
60 65
53 60
65 54
61 66
55 61
66 56
62 67
57 62
67 58
62 67
59 63
68 60
63 68
61 64
69 62
64 69
63 65
70 64
65 70
65 66
71 66
67 72
67 67
72 68
68 73
69 69
74 70
69 74
71 70
75 72
71 76
73 71
76 74
72 77
75 73
78 76
74 79
77 74
79 >77
75 80
Option B: Cumulative Noise Impact Criteria Presentation The impact criteria presentation for evaluating existing noise to project noise cumulatively is presented in this option.

In certain cases, the cumulative form of the noise criteria shown in Figure 4-3 can be used. These cases involve projects where changes are proposed to an existing transit system, as opposed to a new project in an area previously without transit. Such changes might include operations of a new type of vehicle, modifications of track alignments within existing transit corridors, or changes in facilities that dominate existing noise levels. In these cases, the existing noise FEDERAL TRANSIT ADMINISTRATION 28

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sources change because of the project, and so it is not possible to define project noise separately from existing noise. An example would be a commuter rail corridor where the existing noise along the alignment is dominated by diesel locomotive -hauled trains, and where the project involves electrification with the resulting replacement of some of the diesel -powered locomotives with electric trains operating at increased frequency of service and higher speeds on the same tracks. In this case, the existing noise can be determined and a new future noise can be calculated, but it is not possible to describe what constitutes the "project noise." For example, if the existing noise dominated by trains was measured to be an Ldn of 63 dBA at a particular location, and the new combination of diesel and electric trains is projected to be an Ldn of 65 dBA, the change in the noise exposure due to the project would be 2 dB. Referring to Figure 4-3, a 2 -dB increase with an existing noise exposure of 63 dBA would be rated as a moderate impact. Normally the project noise is added to the existing noise to come up with a new cumulative noise, but in this case, the existing noise was dominated by a source that changed due to the project, so it would be incorrect to add the project noise to the existing noise. Consequently, the existing noise determined by measurement is compared with a new calculated future noise, but a description of what constitutes the actual project is complex.

Another example would be a rail corridor where a track is added and grade crossings are closed, potentially resulting in a change in train location and horn operation. Here the "project noise" results from moving some trains closer to some receivers, away from others, and elimination of horns. In this case, the change in noise level is more readily determined than the noise from the actual project elements. In all cases, Figures 4-3 and 4-4 for changes in a transit system results in the same assessment of impact as Figure 4-2 for development of transit facilities in a new area.

The noise impact criteria in Figure 4-3 and Figure 4-4 are presented as an increase in cumulative noise level between the existing and project conditions.

The horizontal axis represents the existing noise exposure and the vertical axis is the increase in cumulative noise level due to the transit project. Note that noise exposure is expressed as Leq(Ihr>for category I and 3 land uses and Ldn for category 2 land use. Since Leq(Ihr) and Ldn are measures of total acoustic energy, any new noise sources in a community will cause an increase, even if the new source level is the same or less than the existing noise level (refer to decibel addition in Appendix B). As shown in Figure 4-3, the criterion for moderate impact is a noise exposure increase of I O dB for an existing noise exposure level of 42 dBA or less, but only a I -dB increase when the existing noise exposure is 70 dBA.

As the existing level of ambient noise increases, the allowable level of transit noise increases, but the total amount that community noise exposure is allowed to increase is reduced. This accounts for the unexpected result that a project exposure which is less than the existing noise exposure can still cause impact.

This is clearer from the examples listed in Table 4-6 which indicate the level of transit noise allowed for different existing levels of exposure. Any increase greater than shown in the table will cause moderate impact.

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0 20
- Severe Impact
-- Moderate
- Impact
No Impact
75 40 45 50 55 60 65 70
Existing Noise Exposure (dBA)
Metric: Category 1 - Leg(1h)
Category 2 - Ldn
BO
Figure 4-3 Increase in Cumulative Noise Levels Allowed by Criteria (Land Use Cat. I & 2)
25 a
C[I
.._ 20—
N
fa -Moderate
um - :5 — Impact
c `
w
L -
• 10 -
- No Impact
a
k
W
5 -
fh -
o
z
0 -Severe Impact
75 40 45 50 55 6D 65 70
Existing Noise Exposure (dBA)
Metric:Category 3 - Leg(1h)
80 Figure 4-4 Increase in Cumulative Noise Levels Allowed by Criteria (Land Use Cat. 3)
This table shows that as the existing noise exposure increases from 45 dBA to 75 dBA, the allowed project noise exposure increases from 5 I dBA to 65 dBA.

However, the allowed increase in the cumulative noise level decreases from 7 dB to 0 dB (rounded to the nearest whole decibel). The justification for this is that people already exposed to high levels of noise should be expected to tolerate only a small increase in the amount of noise in their community. In contrast, if the existing noise levels are quite low, it is reasonable to allow a greater change in the community noise for the equivalent difference in annoyance.

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Note that Table 4-6 was developed for illustrative purposes and the official criteria are included in Figure 4-3 and Figure 4-4 and the associated equations.

Table 4-6 Noise Impact Criteria: Effect on Cumulative Noise Exposure La„ or Leq(Ihr) in dBA (rounded to nearest whole decibel) Existing
Noise
Exposure
Allowable Project
Noise Exposure
Before Moderate
Impact
Allowable
Combined Total
Noise Exposure
Allowable Noise
Exposure
Increase Before
Moderate Impact
45 5I
52 7
50 53
55 5
55 55
58 3
60 57
62 2
65 60
66 I
70 64
71 I
75 65
75 0

4.2 Determine Noise Analysis Level
There are three levels of analysis to evaluate noise on a transit project based on the type and scale of the project, stage of project development, and environmental setting. These levels, described below, are the Noise Screening Procedure, the General Noise Assessment and the Detailed Noise Analysis.

The Noise Screening Procedure, conducted first, defines the study area of any subsequent noise impact assessment. Where there is potential for noise impact, the General Noise Assessment and Detailed Noise Analysis procedures are used to determine the extent and severity of impact. In some cases, a General Noise Assessment may be all that is needed. However, if the proposed project is near noise -sensitive land uses, and it appears at the outset that the impact would be substantial, it is prudent to conduct a Detailed Noise Analysis.

Conduct the noise screening procedure and then determine the appropriate noise analysis option.

Noise Screening Procedure — The Noise Screening Procedure is a simplified method of identifying study area receivers or locations where a project may have the potential for noise impacts from transit projects. This procedure accounts for impact criteria, the type of project, and noise -sensitive land uses. If no noise -sensitive land uses or receivers are present in the analysis area, then no further noise assessment is needed. If noise -sensitive receivers are identified, then proceed to conduct a General Assessment and/or a Detailed Assessment.

The Noise Screening Procedure steps are provided in Section 4.3.

General Noise Assessment — The General Noise Assessment is used to examine potentially impacted areas identified in the screening step by examining the location and estimated severity of noise impacts. This procedure considers noise source and land use information likely to be available at an early stage in the project development process. Estimates are made of project noise levels and of existing noise conditions to model the location of a noise impact contour FEDERAL TRANSIT ADMINISTRATION 3 I

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that defines the outer limit of an impact corridor or area. This modeling method uses transit -specific noise and adjustment data (in tabular and graphical form) for the noise computations.

For many smaller projects, this assessment may be sufficient to define impacts and determine whether noise mitigation is necessary. The procedure can be used in conjunction with established highway noise prediction procedures to compare highway, transit, and multimodal alternatives. If an assessment is needed to inform the decision on transit mode and general alignment in a corridor, the General Noise Assessment procedures should be used, and not the Detailed Noise Analysis, which requires more detailed information.

The General Noise Assessment procedure is provided in Section 4.4. FTA has also developed an Excel spreadsheet to more simply conduct the General Noise Assessment. It is on FTA's website at http://www.fta.dot.gov/ 12347 2233.html.

Detailed Noise Analysis — The Detailed Noise Analysis procedure is a comprehensive assessment method that produces the most accurate estimates of noise impacts for a proposed project. It is important to recognize that use of the Detailed Noise Analysis methods will not provide more accurate results than the General Noise Assessment unless more detailed and case -specific input data are used.

The project must be defined to the extent that location, alignment, transit mode, hourly operational schedules during day and night, speed profiles, plan and profiles of guideways, locations of access roads, and landform topography (including terrain and building features) are determined. A detailed Noise Analysis is often accomplished at the development of the final environmental impact statement (FEIS), record of decision (ROD), or combined FEIS/ROD in the NEPA process, when the preferred alternative is undergoing refinements to mitigate its adverse impacts. However, these project details may not be available until the final design phase, requiring that the detail noise analysis be conducted after the NEPA process is complete. However, it is recommended that the detailed analysis be conducted earlier for controversial projects or projects with highly noise -sensitive sites close to tracks.

A Detailed Noise Analysis may be warranted as part of the development of an environmental assessment (EA) if there are potentially severe impacts due to the proximity of noise -sensitive land uses.

In some cases, decisions on appropriate noise mitigation measures can be made based on the results of the General Noise Assessment. But if costly measures may be needed, it is generally recommended that a Detailed Noise Analysis be conducted to verify the need and design of the noise mitigation. The Detailed Noise Analysis is always appropriate under two sets of circumstances:
■ For a major transit project with likely noise impacts after the preferred alternative has been selected.
■ For any other transit project where potentially severe impacts are identified at an early stage.

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Noise impacts may occur for relatively minor transit projects when the project is near noise -sensitive sites, particularly residences. In this case, completing a Detailed Noise Analysis is recommended. Some examples include:
• A terminal or station sited adjacent to a residential neighborhood • A maintenance facility located near a school
• A storage yard adjacent to residences
• An electric substation located adjacent to a hospital The Detailed Noise Analysis procedure is provided in Section 4.5.

4.3 Evaluate Impact: Noise Screening Procedure
Identify the potential for impact using the Noise Screening Procedure described below.

Step I: Identify Project Type
Identify the project type using Table 4-7 and confirm the assumptions in Table 4-8 are appropriate for the project.

The noise screening procedure is intended to be conservative to broadly capture the potential for impact with minimal effort. To make the procedure conservative, the project system must be assumed to be operating under relatively high -capacity conditions, which would produce more noise than normal operating conditions. In addition, the assumptions in Table 4-8 were made using the lowest threshold of impact (50 dBA) from the criteria curves in Figure 4-2. Clarification can be obtained from FTA on special cases that are not represented in this section.

If the assumptions in Table 4-8 are not appropriate for the project, make adjustments to the screening distances in Table 4-8 according to the methodology in Section 4.4 or the FTA spreadsheet model.

Step 2: Determine the Screening Distance
Determine the appropriate screening distance considering the type of project and shielding from intervening buildings.
2a. Determine the appropriate screening distance column in Table 4-7.

Option A: Buildings in the Sound Paths — Use the screening distances in the "Intervening Buildings" column.

Option B: Buildings Not in the Sound Paths — Use the distances in the "Unobstructed" column.
2b. Adjust these distances according to the methodology in Section 4.4, or the FTA spreadsheet model, if the assumptions in Table 4-8 are not appropriate for the project. The appropriate screening distance is where the project noise reaches 50 dBA for the appropriate metric. If the assumptions in Table 4-8 are not appropriate for a commuter rail grade crossing project where horns and FEDERAL TRANSIT ADMINISTRATION 33

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warning bells are used, use the FRA horn noise model available from the FRA website to develop the screening distance distance (49 CFR § 222).(21) Step 3: Identify Study Area
Apply the screening distances as follows to identify the study area. The study area is intended to be sufficient/y large to encompass all potentially impacted locations.

Option A: Fixed Guideway Transit Sources — Apply the screening distance from the guideway centerline.

Option B: Highway/Transit Sources (e.g., Bus) — Apply the screening distance from the nearest ROW Tine on both sides of a highway or access road.

Option C: Small Stationary Facilities — Apply the screening distance from the center of the noise -generating activity.

Option D: Stationary Facility Spread Over a Large Area — Apply the screening distance from the outer boundary of the proposed project site.

Step 4: Locate Noise -Sensitive Land Uses
Locate all noise -sensitive land uses within the study area using Table 4-3.

See Section 4. I for more information on noise -sensitive land uses. Include all categories of noise -sensitive land uses in this step.

If no noise -sensitive land uses are identified, no further noise analysis is needed. If one or more of the noise -sensitive land uses are in the study area, proceed to Section 4.4 and complete a General Noise Assessment.

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Table 4-7 Screening Distance for Noise Assessments
Project Systems
Screening Distance, ft*
Unobstructed Intervening Buildings
Fixed -Guideway Systems
Commuter Rail Mainline
750
375
Commuter Rail Station
With Horn Blowing
1,600
1,200
Without Horn Blowing
250
200
Commuter Rail Road Crossing with Horns and Bells
1,600
1,200
RRT
700
350
RRT Station
200
100
LRT
350
175
Streetcar
200
100
Access Roads to Stations
100
50 Low and Intermediate
Capacity Transit
Steel Wheel
125
50 Rubber Tire
90 40
Monorail
175
70 Yards and Shops
1000
650
Parking Facilities
125
75 Access Roads to Parking
100
50 Ancillary Facilities: Ventilation Shafts
200
100
Ancillary Facilities: Power Substations
250
125
Bus Systems
Busway
500
250
Bus Rapid Transit (BRT) on exclusive roadway
200
100
Bus Facilities
Access Roads
100
50 Transit Mall
225
150
Transit Center
225
150
Storage & Maintenance
350
225
Park & Ride Lots w/Buses
225
150
Ferry Boat Terminals
300
150
*Measured from centerline of guideway for fixed -guideway sources, from the ROW on both sides of the roadway for highway/transit sources, from the center of noise -generating activity for stationary sources, or from the outer boundary of the proposed project site for fixed facilities spread out over a large area.

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Table 4-8 Assumptions for Screening Distances for Noise Assessments Type of Project Operations
Speeds*
Metric**
Fixed -Guideway Systems
Commuter Rail Mainline
66 day /12 night; I loco, 6 cars
55 mph
Ldn
Commuter Rail
Station
With Horn Blowing
22 day / 4 night
N/A
Lan
Without Horn Blowing
22 day / 4 night
N/A
Lan
Commuter Rail -Highway Crossing with Horns
and Bells
22 day / 4 night
55 mph
Ldn
RRT
220 day / 24 night; 6 -car trains
50 mph
Lan
RRT Station
220 day 124 night
20 mph
Ldn
LRT
150 day / 18 night; 2 artic veh.
35 mph
Lan
Streetcar
150 day / 18 night
25 mph
Lan
Access Roads to Stations _
1000 cars, 12 buses
35 mph
Leg( Ihr)
Low and
Intermediate
Capacity Transit
Steel Wheel
220 day / 24 night
30 mph
Lan
Rubber Tire
220 day / 24 night
30 mph
Lan
Monorail
220 day / 24 night
30 mph
Lan
Yards and Shops
20 train movements
N/A
Leq(Ihr)
Parking Facilities
I000 cars
N/A
Leq(Ihr)
Access Roads to Parking
1000 cars
35 mph
Leg('hr)
Ancillary Facilities: Ventilation Shafts
Rapid Transit in Subway
50 mph
Ldn
Ancillary Facilities: Power Substations
Sealed shed, air conditioned
N / A
Lan
Bus Systems
Busway
30 buses, 120 automobiles
50 mph
Leg('hr)
BRT on exclusive roadway
30 buses
35 mph
Leq(Ihr)
Bus Facilities
Access Roads
1000 cars
35 mph
Leg(' hr)
Transit Mall
20 buses
N/A
Leq(Ihr)
Transit Center
20 buses
N/A
Leg('hr)
Storage & Maintenance
30 buses
N/A
Leq(Ihr)
Park & Ride Lots
w/Buses
1000 cars, 12 buses
N/A
Leg('hr)
Ferry Boat Terminals
8 boats with horns used in
normal docking cycle
N/A
Leg( Ihr)
*N/A = not applicable
*Leq(Ino = the loudest hour of project related activity during hours of noise sensitivity.

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4.4 Evaluate Impact: General Noise Assessment
The General Noise Assessment should be completed after the Noise Screening Procedure (Section 4.3), through which noise -sensitive receivers have been identified. This can be completed either by using the General Noise Assessment Procedure described below or using the FTA General Noise Assessment Spreadsheet found on the following FTA website:
http://www.fta.dot.gov/ 12347_2233.htmI.

Assumptions are used throughout the General Noise Assessment. If the listed assumptions are not appropriate for the project and good engineering judgement cannot be used by following the General Noise Assessment procedure, proceed to a Detailed Noise Analysis or consult with the FTA Regional office.

Major steps in the General Noise Assessment procedure and recommended workflow are shown in Figure 4-5 and listed below. Four examples of General Noise Assessments are given at the end of this section. Many of these concepts are explained in greater detail in the context of a Detailed Noise Analysis in Section 4.5.

Step I: Identify Noise -Sensitive Receivers — Identify noise -sensitive receivers (Section 4.3) and their proximity to the project and major noise sources.

Step 2: Determine Project Noise Source Reference Levels — Determine the project noise sources and reference levels. Then, estimate the project noise exposure at the reference distance of 50 ft considering operational characteristics with preliminary estimations of the effect of mitigation.

Step 3: Estimate Project Noise Exposure by Distance — Estimate project noise exposure at distances beyond 50 ft considering propagation characteristics using a simplified procedure.

Step 4: Combine Noise Exposure from All Sources — Combine all sources associated with the project to predict the total project noise at the receivers.

Step 5: Measure Existing Noise Exposure — Measure the existing noise or estimate the existing noise exposure using a simplified procedure.

Step 6: Inventory Impacts
Option A: Tabulate the change in noise (existing vs. estimated project noise) at each noise -sensitive receiver or cluster, identifying all moderate and severe impacts.

Option B: Take inventory of noise -sensitive receivers that fall within the moderate and severe noise contours.

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Operatioinal
Characteristics
Step 7: Determine Noise Mitigation Needs — Evaluate the need for mitigation and repeat the General Noise Assessment with proposed mitigation.

Project
Sources
Reference
SEL, 50 ft
Loin, 50 ft
Leq, 50 ft
Exposure
vs Distance
Curve
Apply Noise
Mitigation
Propagation
Characteristics
Study Area
Characteristics
Noise Impact
Criteria
Location of
Noise -Sensitive
Sites
Figure 4-5 Procedure for General Noise Assessment
Noise mpact
Inventory
Existing Noise
Exposure
Step I: Identify Noise -Sensitive Receivers
Determine the proximity of noise -sensitive land uses identified in Section 4.3 to the project and to the nearest major roadways and railroad lines.

I a. When necessary, use windshield surveys or detailed land use maps to confirm the location of noise -sensitive land uses.

I b. For land uses more than 1,000 ft from major roadways or railroad mainlines, obtain an estimate of the population density in the immediate area, expressed in people per square mile. Distances to roadways or railroads, or population density, will be used later to estimate the existing FEDERAL TRANSIT ADMINISTRATION 38

TRANSIT NOISE AND VIBRATION IMPACT ASSESSMENT MANUAL
noise level. Coordinate with the Metropolitan Planning Organization (MPO) for population densities at an appropriate level of detail.

Step 2: Determine Project Noise Source Reference Levels Determine the general source reference level for each project noise source.

Classify all project noise sources as fixed -guideway transit, highway/transit, or stationary facility and determine the source reference levels. Note that a major fixed -guideway system will have stationary facilities associated with it and that a stationary facility may have highway/transit elements associated with it.

Option A: Fixed -guideway Transit Sources — For this manual, fixed - guideway transit sources include commuter rail, RRT, LRT, streetcar, AGT, monorail, and magnetically levitated vehicles (maglev). For commuter railroads and LRT systems, the crossing of streets and highways at -grade is likely, and in that case, warning devices should be included in the assessment. At an early project stage, the information available for a General Noise Assessment includes:
• Candidate transit mode
• Guideway options
• Time of operation
• Operational headways
• Design speed
• Alternative alignments
This information is not sufficient to predict noise levels at all locations along the ROW. Therefore, use conservative estimates (e.g., maximum (expected) design speeds and operations at design capacities) to estimate worst -case noise levels.

First choose the appropriate fixed -guideway transit source reference level and then predict the noise exposure at 50 ft in terms of Leq(Ihr) and Ldn.

A.i. Choose the reference source noise levels 50 ft from the track for one vehicle in terms of Sound Exposure Level (SEL) using Table 4-9. See Appendix B for a detailed explanation of SEL. Note that the SEL reference speed is 50 mph, unless otherwise noted.

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Table 4-9 Reference SEL's 50 ft from Track and at 50 mph, One Vehicle Source
Type
Reference Conditions
Reference
SEL (SELref),
dBA
Commuter
Rail, At -Grade
Locomotives
Diesel-electric, 3000 hp, throttle 5
92 Electric
90 Diesel Multiple Unit (DMU)
Diesel -powered, 1200 hp
85 Horns
Within '/ mile of grade crossing
110
Cars
Ballast, welded rail
82 Rail Transit and Streetcars at 50 mph
At -grade, ballast, welded rail
82 Rail Transit and Streetcars at 25 mph
At -grade, ballast, welded rail
76 Transit whistles / warning devices
Within 1/8 mile of grade crossing
93 AGT
Steel Wheel
Aerial, concrete, welded rail
80 Rubber Tire
Aerial, concrete guideway
78 Monorail
Aerial straddle beam
82 Maglev
Aerial, open guideway
72 A.ii. Collect the following data:
• Number of train passbys during the day (7 a.m. to I O p.m.) and night (10 p.m. to 7 a.m.) for category 2 land uses
• Maximum number of train passbys during hours that category I or category 3 land uses are normally in use (typically the peak hour train volume)
• Number of vehicles per train for each time period for category 2 land uses (if this number varies during the day or night, take the average) • Maximum number of vehicles per train during hours that category I or category 3 land uses are normally in use (typically the peak hour train volume)
• Train speed in mph (maximum expected)
• Guideway configuration
• Location of highway and street grade crossings, if any • If this process is repeated to estimate the effect of proposed noise mitigation, include the noise barrier location
A.iii. Calculate the noise exposure at 50 ft in terms of Leq(Ihr):
• Calculate Leq(Ihr) for each source using the appropriate equations in Table 4-10.
• Compute Leq(Ihr).Combo using Eq. 4-6. It may be necessary to compute the combined totals with and without warning horns. Some neighborhoods along the corridor may be exposed to horn noise, but some may not.

A.iv. Calculate the noise exposure at 50 ft in terms of Ldn:
• If the project noise will affect any residential receivers, calculate the Ldn using the combined Leo hr) for both the daytime and nighttime periods separately, using the appropriate equations in Table 4-10. • It may be necessary to calculate Ldn with and without warning horns, as in the previous step.

Note that the equations in Table 4-10 include terms to account for a difference in speed from the 50 mph reference speed and a numerical adjustment to account for the one -hour time period for this metric. For FEDERAL TRANSIT ADMINISTRATION 40

TRANSIT NOISE AND VIBRATION IMPACT ASSESSMENT MANUAL
more information on the numerical adjustment to represent the time period of interest, see Appendix B.I.4.4.

Table 4- I 0 presents an estimate of the noise reduction potentially provided by wayside noise barriers that can be used when assessing mitigation options in a General Noise Assessment. If impact is determined during the General Noise Assessment, repeat the procedure and include proposed mitigation according to Section 4.4, Step 7. See Section 4.5, Step 7 for a complete description of the benefits resulting from various noise mitigation measures that can be evaluated with a Detailed Noise Analysis.

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Table 4-10 Computation of Noise Exposure at 50 ft for Fixed -Guideway General Noise Assessment Locomotives*
Leq(Ihr)at 50 ft
S
Leq.Loco(lhr) = SELref + 10log(NLoco) + Klog(50) + 10 log(V) — 35.6 Eq. 4- I Locomotive
Warning
Horns**
Leq(Ihr)at 50 ft
= o
Leq.LHorns(lhr) SELref + 10 log — 35.6 Eq, 4-2
Rail Vehiclest
Leq(Ihr)at 50 ft
S
Leq.Rcars(ihr) = SELref + 10 log(Ncars) + 201og(50) + 10 log(V) — 35.6 + Adjtrack Eq. 4-3 Streetcars
(25 h or
slower)
Leq(Ihr) at 50 ft
Legscars(lhr) = SELref + 101og(Ncars) + 21og(5 ) + 10log (V) — 35.6 + Adjtrack Eq. 4-4 Transit
Warning Horns
Leq(Ihr)at 50 ft
S
Leq.THorns(1hr) = SELref — 10 log + 10 log — 35.6 Eq. 4-5 Combined
Locomotive and
transittt
Leq(Ihr) at 50 ft
Leq.Loco(1hr) Leq.RCars(1hr) Leq.SCars(1hr)
Leg.combo(1nr) = 101og(10( /10) + 10( /10) + 10( /io)
+ 10(Leq.LHorns(1hr)/10) + 10( Leq.THorns(1hr)/10) Eq. 4-6 Daytime
La at 50 ft
Ld = Leq(lhr) where V = Vd, NLoco = Nd (Ioco events), and Ncars = Nd (car events) Eq. 4-7 Nighttime
Ln at 50 ft
Ln = Leq(lhr) where V = Vn, NLoco = Nd (loco events), and Ncars = Nd (car events) Eq. 4-8 Day/Night
Lai at 50 ft
Ld (Ln+10)
kin = 10log (15 x 10( /io) + 9 x 10( /10)) — 13.8 Eq. 4-9 NLoco = average number of locomotives per train
K = constant
-10 for passenger diesel
0 for DMUs
+10 for electric
S = train speed, mph
V = average hourly volume of train traffic, trains per hour Ncars = average number of cars per train
Adjtrack = constant
+5 for jointed track or for a crossover within 300 ft
+4 for aerial structure with slab track (except AGT and monorail) +3 for embedded track on grade
-5 if a noise barrier blocks the line of sight
Vd = average hourly daytime volume of train traffic, Vn = average hourly nighttime volume of train traffic, trains per hour trains per hour
number o f trains, 7 a.m. to 10 p. m. number o f trains,10 p. m. to 7a. m. 15 = 9
Nd = average hourly number of events that occur Nn = average hourly number of events that occur during during daytime (7 a.m. to 10 p.m.) nighttime (10 p.m. to 7 a.m.) number o f events between 7 a.m. to 10 p. m. number o f events between 10 p. m. to 7 a.m. 15 9
* Assumes a diesel locomotive power rating at approximately 3000 hp. ** Based on FRA's horn noise model ( http://www.fra.dot.gov/eLib/Details/L0409 I ). t Includes all commuter rail cars, transit cars, streetcars above 25 mph, AGT and monorail. t Only include appropriate terms.

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Option B: Highway/Transit Sources — The highway/transit type sources include most transit modes that do not require a fixed -guideway. Examples are high -occupancy vehicles, such as buses, commuter vanpools and carpools. Use the instructions below to estimate source noise levels for projects that involve these types of vehicles and are using FTA's environmental review procedures.

At an early project stage, the information available for a General Noise Assessment includes:
• Vehicle type
• Transitway design options
• Time of operation
• Typical headways
• Design speed
• Alternative alignments
This information is not sufficient to predict noise levels at all locations along the ROW; therefore, use of conservative estimates (e.g., maximum (expected) design speeds and operations at design capacities) to estimate worst -case noise impact levels is recommended. The procedure is consistent with FHWA's highway noise prediction method. The reference SEL levels in Table 4-I I correspond to FHWA's source emission levels and speed coefficients for buses and automobiles.(zz)
B.i. Using Table 4-I I, choose the appropriate reference source noise levels 50 ft from the roadway in terms of SEL. Note that the SEL reference speed is 50 mph, unless otherwise noted.

Table 4-11 Source Reference Levels at 50 ft from Roadway, 50 mph Source*
Reference SEL, dBA
Automobiles and Vans
74 Buses (diesel -powered)
82 Buses (electric)
80 Buses (hybrid)
83**
* Assumes normal roadway surface conditions.
** For hybrid buses, determine Reference SEL on a
case -by -case basis because they vary, and data are
scarce.

B.ii. Collect the following data:
• Number of vehicle passbys during the day (7 a.m. to I 0 p.m.) and night (I 0 p.m. to 7 a.m.) for each vehicle type in Table 4- I I, if a category 2 land use is present
• Number of vehicle passbys during hours that category I or category 3 land uses are normally in use, each vehicle type in Table 4- I 1 • Speed (maximum expected)
• Transitway configuration (with or without noise barrier) B.iii. Calculate the noise exposure at 50 ft in terms of Leq(Ihr). Calculate Leq(Ihr) for each source using the appropriate equations in Table 4-I2.

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B.iv. Calculate the noise exposure at 50 ft in terms of Ldn. If the project noise will affect any residential receivers, calculate the Ldn using the combined Leq(Ihr) for both the daytime and nighttime periods separately, using the appropriate equations in Table 4-12.

Note that the equations in Table 4-12 include terms to account for a speed other than the 50 mph reference speed and a numerical adjustment to account for the one -hour time period for this metric. For more information on the numerical adjustment to represent the time period of interest, see Appendix B.I.4.4.

Table 4-12 presents an estimate of noise reduction potentially provided by wayside noise barriers. This is considered illustrative given that barriers are the most common noise mitigation measure. See Section 4.5, Step 7 for a complete description of the benefits resulting from noise mitigation. If impact is determined during the General Noise Assessment without mitigation, repeat the procedure and include proposed mitigation.

Table 4-I2 Computation of Leq(Ihr) and Ld„ at 50 ft for Highway/Transit General Noise Assessment Leg(' hr) at 50 ft
Leq(lhr) = SELref + 10 log(V) + Cslog(SQ) — 35.6
SO
Eq. 4-I0
Daytime
Ldat50ft
L = LAe where V = Vd
d lhr
q( )
Eq. 4-1 I
Nighttime
L,, at 50 ft
Ln = LAeq(lhr) where V = V,
Eq. 4- 12

Ld„ at 50 ft
Ldn = 10109(15 x 10(Ld/lo) + 9 x 10((Ln+10)/10)) - 13.8 Eq. 4-13
Barrier
Adjustment
= -5 for noise barriers
V
Cs
S
Vd
V,
= hourly volume of vehicles, vehicles per hour
= Speed constant
15 for diesel buses
28 for electric buses
21 for hybrid buses(23)
30 for automobile and van pools
= average vehicle speed, mph
= average hourly daytime volume of vehicles, vehicles per hour _ total number o f vehicles, 7 a.m. to 10 p.m.
15 = average hourly nighttime volume of vehicles, vehicles per hour _ total number o f vehicles, 10 p. m. to 7 a.m.
9 Option C: Stationary Sources — Stationary sources include fixed transit system facilities. New transit facilities undergo a site review for best location that considers the noise sensitivity of surrounding land uses. Although many facilities such as bus maintenance garages are usually located in industrial and commercial areas, some facilities such as bus terminals, ferry terminals, train stations, and park -and -ride lots may be placed near residential neighborhoods where noise impact may occur. Access roads to some of these facilities may also FEDERAL TRANSIT ADMINISTRATION 44

TRANSIT NOISE AND VIBRATION IMPACT ASSESSMENT MANUAL
pass through noise -sensitive areas. Noise from access roads is treated according to the procedures described in the Highway/Transit Sources category. In a General Noise Assessment, only the prominent features of each fixed facility are considered in the noise analysis.

C.i. For small facilities, using Table 4-13, determine the reference source noise levels 50 ft from the center of the site in terms of SEL. The source reference levels given in the table are based on measurements for the peak hour of operation of a typical stationary source of the noted type and size.

A large facility, such as a rail yard, is spread out over considerable area with various noise sources with different noise levels depending on the layout of the facility. Specifying a single reference SEL for the facility at 50 ft from the center of the site could be misleading if all of these different noise sources are not represented. Therefore, the reference distance should be the equivalent distance of 50 ft, which is determined by estimating the noise levels from the center of the site at a distance far enough to capture all noise sources and projecting back to 50 ft from the center of the site. This approach allows for a conservative estimate of noise for all surrounding areas and the equivalent noise can be considered as concentrated at the center of the site. If the location of noise sources is known, then the distance should be taken from the point of the noisiest activity on the site (e.g., the dock in the case of ferry boat operations) instead of the center of the site.

Table 4-13 Source Reference Levels at 50 ft from Center of Site, Stationary Sources Source
Reference
SEL, dBA
Reference Conditions
Rail System
Yards and shops
I I8
20 train movements in peak activity hour
Layover tracks (commuter rail)
109
I train with diesel locomotive idling for I hour
Crossing signals
109
3600 second duration
Bus System
Storage yard
I I I
100 buses accessing facility in peak activity hour
Operating facility
114
100 buses accessing facility, 30 buses serviced and
cleaned in peak activity hour
Transit center
101
20 buses in peak activity hour
Ferry Terminal
Ferry boat (no fog horn sounded)
97 4 ferry boat landings in I hour
Ferry boat (fog horn sounded)
100
Parking Garage
92 1000 -car capacity in peak activity hour
Park & Ride Lot 101
12 buses, 1000 cars in peak activity hour
C.ii. Collect the following data:
■ Number of layover tracks and hours of use
• Number of buses, if different from assumed reference conditions (if this number varies during the day or night, take the average) • Number of ferry boat landings, if different from assumed reference conditions (if this number varies during the day or night, take the average)
• Actual capacity of parking garage or lot
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C.iii. Calculate Lego nr> at 50 ft. Calculate Leq(inro for each source using the appropriate equations in Table 4-14.

C.iv. Calculate Ldn at 50 ft. If the project noise will affect any residential receivers, calculate the Ldn using the combined Leq(inr) for both the daytime and nighttime periods separately, using the appropriate equations in Table 4-14.

The equations in Table 4-14 include a numerical adjustment to account for the one -hour time period for this metric. See Appendix B.1.4.4 for more information on the numerical adjustment.

Table 4-14 presents an estimate of noise reduction potentially provided by noise barriers at the property line. Only approximate locations and lengths for barrier or other noise mitigation measures are developed during a General Noise Assessment to provide a preliminary indication of the costs and benefits of mitigation. A Detailed Noise Analysis of the preferred alternative is usually warranted following the General Noise Assessment (if it predicts any impacts) to verify impacts and design the mitigation.

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Table 4-14 Computation of Lego hr) and Ld„ at 50 ft for Stationary Source General Noise Assessment* Leg(' hr) at 50 ft
Leq(lhr) = SELYef + CN — 35.6 Eq. 4- 14
Daytime at
ft
1 LAeq(ihr)
Ld = 101og((15) > 10( i10)) Eq. 4-I5
7am-l0pm
Nighttime
Lr at 50 ft
1 (LAeq(ihr)�10)
4 = 101og((9) 10 ) Eq. 4- 16
l0pm-7am
Ldn at 50 ft
Ldn = 101og(15 x 10( L i10) + 9 X 10((L"+10)/to)) — 13.8 Eq. 4-17 Barrier
Adjustment
= -5 for noise barrier at property line
Volume
Adjustment
= CN
= 101og(20) Rail yards and shops
= 101og(NT) Layover tracks
= 101og(100) Bus storage yard
= 101og(200NB +1‘60) Bus operating facility
= 101og(20) Bus transit center
= 101og(4) Ferry terminal
= 101og( NA Parking
loo o) garage
Park & ride lot
= 101og(2000 +
z4)
E
= 1010g(
)
3600 Crossing signals
NT = average number of trains per hour during the day (7AM to I 0PM) or night (10PM to 7AM)
NB = average number of buses per hour during the day or night NF = average number of ferry boat landings per hour during the day or night Ns. = average number of buses serviced and cleaned per hour during the day or night NA = average number of automobiles per hour during the day or night E = average hourly duration of events, sec during the day or night * If any of these numbers is zero, omit that term.

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Step 3: Estimate Project Noise Exposure by Distance
Estimate the project noise exposure for locations beyond the reference distance, such as for noise -sensitive land uses.

In the previous step, noise exposure at the reference distance of 50 ft was calculated for the various noise sources. This step describes how to estimate the project noise exposure beyond (or, if needed, closer than) the reference distance, such as at noise -sensitive land uses locations. This procedure estimates the source's noise exposure as a function of distance. Adjustments are provided to account for shielding attenuation from rows of buildings. 3a. Select the appropriate distance correction curve (Fixed -Guideway & Highway or Stationary) from Figure 4-6. The Fixed -Guideway & Highway curve refers to line sources while the Stationary curve is refers to point sources. The distance correction factor (Cdistance) is 0 dB at 50 ft. 3b. Choose a distance other than 50 ft, such as the distance to a receiver.

Determine the correction factor using Figure 4-6 or calculate using the equations in Table 4-15.(m) For distances beyond I ,000 ft, the equations in Table 4-15 can be used; however, ground effects have an upper limit and atmospheric conditions may affect propagation characteristics. More detailed calculation methods may be required to account for those effects beyond 1,000 ft.

Distance Correction Value, dB
0 10
- 20
- 30
-40
Fixed -guideway & Highway
Stationary
50 60 80 100
0 10
20 30
40 150 200 250 300 400 500 600 800 1000
Distance, ft
Figure 4-6 Curves for Estimating Exposure vs. Distance in General Noise Assessment oi Note that the curves and equations assume acoustically soft ground beyond a distance of 50 ft. See Table 4-27 for more detailed calculation of ground attenuation.

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Table 4-15 Distance Correction Factor Equations for General Noise Assessment Source
Equation
Stationary Sources
D
Cdistance =—251og( 3)
Eq. 4-I8
Fixed -guideway and Highway
D
Cdistance =—151og(50)
Eq. 4-I9
D = distance, ft
3c. Apply the distance correction (Cdtstance) to the project noise exposure at 50 ft (Section 4.4, Step 2) using the following equation:

Ldistance = L50 + Cdistance
where:

Ldistance = Ldn or Leq(lhr) at the new distance in feet L50 = Ldn or Leq(ihr) at 50 ft
Eq. 4-20
3d. Repeat Step 3c for each source -receiver distance from the project. A noise exposure vs. distance curve can be created, if desired, by calculating the noise exposure for all distances of interest and plotting a curve. This curve can be used to assist in determining the noise impact contour for the first row of unobstructed buildings. This plot can be used to display noise from both unmitigated and mitigated conditions to assess the potential benefits from mitigation measures.

For second row receivers and beyond, it is necessary to account for shielding attenuation from rows of intervening buildings. Without accounting for shielding, impacts may be substantially overestimated. Use the following general rules to account for the effect of shielding from intervening rows of buildings:
• Assign 4.5 dB of shielding attenuation for the first row of intervening buildings only.
• Assign 1.5 dB of shielding attenuation for each subsequent row, up to a maximum total attenuation of 10 dB.

Step 4: Combine Noise Exposure from All Sources
Combine all sources to predict the total project noise at the receivers using the equations in Table 4-16, once propagation adjustments have been made for the noise exposure from each source separately (fixed -guideway, highway/transit, and stationary).

Table 4-I6 Computing Total Noise Exposure
Total Le t) from all sources
for the hour of interest:

Leq.rotat(1hr) = 101og(�aii sources 10Le9�10)
Eq. 4-21
Total Ldp from all sources
Ldn.totai = 101og(�aii sources 10Ldn/10)
Eq. 4-22
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Step 5: Estimate Existing Noise Exposure
Measure the existing noise or estimate the existing noise exposure using a simplified procedure.

Existing noise in the project vicinity must be quantified and compared to the project noise to determine the potential noise impact. It is generally recommended to measure existing noise, especially at locations known to be noise -sensitive, but if measurement results are not available then they must be estimated. In the Detailed Noise Analysis, the existing noise exposure is usually based on noise measurements at representative locations in the community.

It is not necessary or recommended that
existing noise exposure be determined by
measuring at every noise -sensitive
location in the project area. Rather, the
recommended approach is to
characterize the noise environment for
"clusters" of sites based on measurements
or estimates at representative locations in
the community. Because of the sensitivity
of the noise criteria to the existing noise
exposure, careful characterization of pre -
project ambient noise is important.

Guidelines for selecting representative
receiver locations and determining
ambient noise are provided in Appendix D and Appendix E, respectively.

Changes to Existing Transit
For projects that propose
changes to an existing transit
system, such as a rehabilitation
project, the project noise can
include changes to the existing
noise because of the project,
and so it is not possible to
define project noise separately.

For these projects, refer to
Section 4. I , Step 3 — Option B,
on using the cumulative
noise criteria.

This section describes how to estimate the existing noise in the project study area from general data available early in project planning. The procedure uses Table 4-17, where a neighborhood's existing noise exposure is based on proximity to nearby major roadways or railroads, or on population density. For areas near major airports, published aircraft noise contours can also be used to estimate the existing noise exposure. The process is as follows:
5a. Obtain scaled mapping and aerial photographs showing the project location and alternatives. A scale of I inch = 200 or 400 ft is convenient for the accuracy needed in the noise assessment. The size of the base map should be sufficient to show distances of at least 1000 ft from the center of the alignment or property center, depending on whether the project is a line source (fixed guideway/ roadway) or a stationary facility. These data are commonly available from local transit agencies and a number of publicly available online tools. 5b. Estimate the existing noise exposure by estimating the noise from major roads and railroad lines or by population density. First, evaluate the site's proximity to major roads and railroad lines including those that are included in the project. If these noise sources are far enough away that ambient noise is dominated by local streets and community activities, estimate the existing noise based on population density. To choose the appropriate existing noise exposure, compare noise levels from each of the three categories —Roadways, Railroads, and Population Density —and select the lowest level. In case of a FEDERAL TRANSIT ADMINISTRATION 50

TRANSIT NOISE AND VIBRATION IMPACT ASSESSMENT MANUAL
lightly used railroad (one train per day or less) select the Population Density category. Existing noise levels are presented in Table 4-17. Refer to Section 4.1, Step 3 — Option B, on using the cumulative noise criteria for projects that propose changes to an existing transit system, such as a rehabilitation project.

Option A: Roadways — Major roadways are separated into two categories for a general noise assessment. Roadways that cannot be described by these two categories are not considered major roadways and would use the Population Density method described below. The roadway categories are as follows:
■ Interstate highway —roadways with 4 or more lanes that allow trucks • Other roadway —parkways without trucks and city streets with the equivalent of 75 or more heavy trucks per hour or 300 or more medium trucks per hour
The estimated roadway noise levels in Table 4-17 are based on data for light to moderate traffic on typical highways and parkways using FHWA highway noise prediction procedures. Where a range of distances is given, the noise exposure estimates are given at the larger distance (note that the traffic noise at the smaller distance is underestimated). For highway noise, distances are measured from the centerline of the near lane for roadways with two lanes, while for roadways with more than two lanes the distance is measured from the geometric mean of the roadway. This distance is computed as follows:
where:

DGM
DN
DF
DGM = V(DN)(DF)
= distance to the geometric mean in feet
= distance to the nearest lane centerline in feet
= distance to the farthest lane centerline in feet
Eq. 4-23
Option B: Railroad Lines — For railroads, the estimated noise levels are based on an average train traffic volume of 5—I0 trains per day at 30-40 mph for main line railroad corridors and the noise levels are provided in terms of Ldn only. Distances are referenced to the track centerline, or in the case of multiple tracks, to the centerline of the rail corridor. Because of the intermittent nature of train operations, train noise will affect the Leq(ihr) only during certain hours of the day, and these hours may vary from day to day. Therefore, to avoid underestimating noise impact when using Leq(ihr) , it is recommended that sites near rail lines are estimated based on nearby roadways or population density unless very specific train information is available.

Option C: Population Density — In areas away from major roadways, noise from local streets or in neighborhoods is estimated using a relationship determined during a research program by EPA.(24) EPA determined that ambient noise can be related to population density in locations away from transportation corridors, such as airports, major roads and railroad tracks, according to the following relation:

Ldn = 22 + 101og(p)
Eq. 4-24
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where:

Ldn
p
= in dBA
= population density in people per square mile
In areas near major airports, published noise contours can be used to estimate the existing noise exposure. The Ldn from such contours should be applied if greater than the estimates of existing noise from other sources at a given location.

Table 4-17 Estimating Existing Noise Exposure for General Noise Assessment Dominant
Existing Noise
Source rce
Distance Noise Sou from Major
*

Population
Density, people
per sq. mi.

Noise Exposure Estimates
Leq
Day
Leq Leq
Evening Night
Ldn
10-50
75 70
65 75
50-100
70 65
60 70
Interstate
100-200
65 60
55 65
Highway**
200-400
60 55
50 60
400-800
55 50
45 55
800 and up
50 45
40 50
10-50
70 65
60 70
50-100
65 60
55 65
Other Roadwayt
100-200
60 55
50 60
200-400
55 50
45 55
400 and up
50 45
40 50
10-30
--
--
--
75 30-60
--
--
--
70 60-120
--
--
--
65 Railwaytt
120-240
--
--
--
60 240-500
--
--
--
55 500-800
--
--
--
50 800 and up
--
--
--
45 1-100
35 30
25 35
100-300
40 35
30 40
300-1000
45 40
35 45
Population
1000-3000
50 45
40 50
3000-10000
55 50
45 55
10000-30000
60 55
50 60
30000 and up
65 60
55 65
* Distances do not include shielding from intervening rows of buildings. Generally, for estimating shielding attenuation in populated areas, assume I row of buildings every 100 ft, 4.5 dB for the first row, and 1.5 dB for every subsequent row up to a maximum of 10 dB attenuation. ** Roadways with 4 or more lanes that permit trucks, with traffic at 60 mph. j- Parkways with traffic at 55 mph, but without trucks, and city streets with the equivalent of 75 or more heavy trucks per hour and 300 or more medium trucks per hour at 30 mph. tt Main line railroad corridors typically carrying 5-10 trains per day at speeds of 30-40 mph.

Step 6: Inventory Noise Impacts
Inventory the potential noise impacts either by comparing the project and existing noise at each noise -sensitive land use or by developing noise impact contours.

Use land use information and assumptions for shielding attenuation from rows of buildings. In some cases, it may be necessary to supplement the land use information or determine the number of dwelling units within a multi -family building with a visual survey. If the objective is to compare major alignment options, it may not be necessary to identify every different type of noise - FEDERAL TRANSIT ADMINISTRATION 52

TRANSIT NOISE AND VIBRATION IMPACT ASSESSMENT MANUAL
sensitive land use. The inventory may include a subset of land uses, including residential and public institutional uses.

Option A is the preferred method as it quantifies the noise impact at each noise -sensitive land use indicating the severity of the impact. Option B may be useful for comparing and narrowing down major alignment options with numerous noise -sensitive land uses.

Option A: Compare existing noise to project noise at each noise - sensitive land use.

A I . Tabulate each individual noise -sensitive land use building and site within the identified screening distance (Section 4.3).

A2. Determine for each noise -sensitive land use the existing noise (Section 4.4, Step 5), the project noise (Section 4.4, Step 3) and the resulting change in noise.

A3. Designate each noise -sensitive land use with either a no, moderate, or severe noise impact based on the criteria in Section 4. I .

A4. Identify all moderate and severe impacts on a project map.

Option B: Develop noise impact contours.

B I . Determine the noise level thresholds at which the project noise would cause moderate and severe impacts using the estimated existing noise exposure from Section 4.4, Step 5 and the noise impact criteria in Figure 4-2.

B2. Determine the distances from the project boundary to the two impact levels using the noise exposure vs. distance curves or equations in Section 4.4, Step 3.

B3. Plot points on a project land use map that correspond to the distances determined in Section 4.4, Step 3. Continue this process for all areas surrounding the project. Connect the plotted points to represent the noise impact contours.

B4. Tabulate all noise -sensitive land use buildings and sites that lie between the impact contours and the project boundary. For residential buildings, an estimate of the number of dwelling units is satisfactory.

B5. Prepare summary tables showing the number of buildings (and estimated dwelling units, if available) within both impact categories.

Specific decibel level noise contours, for example, 65 dBA, can also be plotted if desired. The distances can be determined using the procedure in Section 4.4, Step 3 by substituting the desired decibel level for the impact threshold.

Locations of points will change with respect to the project boundary as the existing ambient exposure changes, the project source levels change, and as shielding effects change. It is recommended to plot points close together to FEDERAL TRANSIT ADMINISTRATION 53

TRANSIT NOISE AND VIBRATION IMPACT ASSESSMENT MANUAL
draw a smooth curve. For a General Noise Assessment, the contours may be drawn through buildings and terrain features as if they were not present. This practice is acceptable considering the level of detail associated with a project in its early stages of development. Example 4- I and Example 4-4 describe the development of noise contours with illustrations.

Step 7: Determine Noise Mitigation Needs
Apply estimates of the noise reduction from proposed mitigation measures (Section

4.4, Step 2), where the assessment shows either severe or moderate impact, and repeat the tabulation of noise impacts.

Note that noise barriers are the only form of mitigation available in a General Noise Assessment. The other mitigation measures are available for a Detailed Noise Analysis. The approximate noise barrier lengths and locations developed in a General Noise Assessment provide a preliminary basis for evaluating the costs and benefits of impact mitigation. This evaluation will provide a conservative estimate of the effect of the mitigation on the identified impacts.

In general, it is recommended to complete a Detailed Noise Analysis for final mitigation measures. However, if impact is identified through a General Noise Assessment and can be mitigated to a level of no impact using the noise reduction estimates included in the General Noise Assessment, a Detailed Noise Analysis may not be needed. Mitigation assumed in the assessment used for the NEPA evaluation must be included in the project as a commitment.

Consult with the FTA Regional office to determine if a Detailed Noise Analysis is required for final mitigation measures.

The following examples illustrate how to complete general noise assessments for varying project types including commuter rail, highway/transit, BRT system, and a transit center.

Example 4- I General Noise Assessment — Commuter Rail
General Noise Assessment for a Commuter Rail System in an Existing Abandoned Railroad Right -of -Way
The following example illustrates the General Noise Assessment procedure for a new fixed -guideway project.

The hypothetical project is a commuter rail system to be built within the abandoned ROW of a railroad. The example covers a segment of the corridor that passes through a densely developed area with population density of 25,000 people per square mile in mixed single- and multi -family residential land uses as shown in Figure 4-7.

The example is presented in two parts: first, a segment where the rail line is grade -separated and a horn is not sounded; and second, an at -grade street -rail crossing where the horn is sounded.

Assumptions
• Project Corridor
Existing population density is 25,000 people per square mile. • Commuter Rail System
Commuter train with one locomotive and a three -car consist on a double -track at -grade system with welded rail. Trains operate with 20 -minute headways during peak hours and I -hour headways during off-peak. Speeds are approximately 40 mph along the corridor.

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Operating
Determine
Estimate
Schedule
Period
Headway
Inbound
(minutes)
Outbound
Trains per hour
Inbound Outbound Total
Period
Total
Daytime
7 a.m. - 8 a.m.
20 20
3 3
6 6
8 a.m. - 4 p.m.
60 60
I
I
2 16
4 p.m. - 6 p.m.
20 20
3 3
6 12
6 p.m. - I 0 p.m.
60 60
I
I
2 8
Nighttime
10 p.m. - I I p.m.
60 60
I
I
2 2
1 I p.m. - 5 a.m.
--
--
--
--
--
--
5 a.m. - 6 a.m.
60 60
I
I
2 2
6 a.m. - 7 a.m.
20 20
I
I
2 2
Part
Project Source Reference
Classify the noise source: Fixed -Guideway
Determine noise source reference
Locomotive: 92 dBA
Cars: 82 dBA
Project Noise Exposure
Determine average hourly daytime
Daytime (7 a.m. - 10 p.m.)
42 trains
Vd 2.8 trains/hour
I: Grade -Separated Street Crossing
Levels at 50 ft
Transit
level from Table 4-9:
at 50 ft
and nighttime volumes of train traffic.
the daytime Leq(Ihr) at 50 ft for the locomotives and rail cars.

S
10log(NLocos) + Klog(5O) + 10log(Vd) — 35.6
40 — 101og(50) + 10log(2.8) — 35.6
A at 50 ft
S
101og(Ncars) + 201og(sO) + 10log(Vd) — 35.6
40 + 201og(sO) + 10log(2.8) — 35.6
at 50 ft
the locomotive and rail cars using Eq. 4-7.
+ 1OLd.RCars110)
+ 10"I in)
50 ft
15 hours
Nighttime (10 p.m. - 7 a.m.)
6 trains
Vn = 0.7 trains/hour
9 hours
Use Eq. 4-I and Eq. 4-3 to calculate
Ld.Locos = SELYef +
= 92 + 10log(1)
= 61.8 dB
Ld.ncars = SELYef +
= 82 + 10log(3)
= 53.7 dBA
Calculate the total daytime Ld for
= 10log(1OLd.Loco�10
Ld.Combo
= 10log(10618/10
= 62.4 dBA at
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Calculate the nighttime Leq(ihr) at 50 ft for the locomotives and rail cars.

S
= SELYe f + 10 log(NLocos) + K log(50) + 101og(Vn) — 35.6 40 = 92 + 10 log(1) — 10log( 50) + 10 log(0.7) - 35.6
= 55.8 dBA at 50 ft
Ln.Locos
Ln.RCars
S
= SELYef + 101og(Ncars) + 20log( so) + 101og(Vn) — 35.6 40 = 82 + 10log(3) + 20log(50) + 10log(0.7) — 35.6
= 47.7 dBA at 50 ft
Calculate the total nighttime Ln for the locomotive and rail cars using Eq. 4-8.

Ln.Combo
= 101og(10Ln.L°c°s/10 10Ln.RCarslo)
= 10log(1055.81i0 + 1047.7/10)
= 56.4 dBA at 50 ft
Calculate Ldn at 50 ft for the project using Eq. 4-9.

Ldn.Combo
= 10log (15 x 10(Ld.combo/10) + 9 x 10((Ln.combo+10)10)) — 13.8 Estimate Existing Noise Exposure
Estimate existing noise at noise -sensitive sites. Since the existing alignment is on an abandoned railroad, the dominant existing noise source can be described by a generalized noise level to characterize a large area.

Use Table 4-17 and population density of 25,000 people per square mile to determine the existing noise level. Unobstructed residences range from 100 to 200 ft from the rail line.

According to Table 4-17: Ldn = 60 dBA
Determine Noise Level and Distance for the Onset Of Impact Determine the noise level for the onset of moderate and severe impact using Figure 4-2 and the existing noise level of 60 dBA. Note that this project is land use category 2 and the appropriate metric is Ldn.

Existing
Noise
Ldn
Onset of Moderate
Impact
Lan
Onset of Severe Impact
Ldn
60 dBA
58 dBA
64 Dba
Determine the distance from the project noise sources to the noise impact contours using the fixed - guideway curve in Figure 4-6 (or the equations in Table 4-I5) and the project impact thresholds obtained above. The project noise level at 50 ft is approximately 64 dBA.

Moderate impact (58 dBA)
58-64= —6 dB
According to Figure 4-6, the distance correction is approximately -6 dB at 120 ft.

Severe Impact (64 dBA)
64 — 64 = 0 dB
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According to Figure 4-6, the distance correction is less than 0 dB at approximately 51 ft.

Project Level
Ldn
Onset of Moderate
Impact
Distance
Onset of Severe
Impact
Distance
64 dBA
120 ft
51 ft
Develop Noise Impact Contours
Draw contours for each affected land use, based on the above table and its distance from the rail line (Figure 4-7). Note that the impact distances listed are in terms of distance to the centerline of the Commuter Rail corridor.

Inventory of Noise Impact
There are six residential buildings within the contours defining moderate impact (shaded in Figure 4-7).

Noise Mitigation
The procedure is repeated assuming a noise barrier to be placed at the railroad ROW line. The barrier serves to reduce project noise from the commuter rail by at least 5 dB. Note that the barrier does not affect the project criteria to be used in determining impact, and the same existing noise levels (as the case without a barrier) are used to determine these thresholds.

In this example, the noise barrier decreases the distance to moderate impact from 120 to 60 ft and eliminates all residential noise impact for this segment of the project area.

Jcpdo
U
LJ
JUfl
120'
Abandoned Rail
I I
Proposed Commuter Rail
120'
yi0DED
3 J
Severe Impact
Moderate Impact
Figure 4-7 Noise Impacts of Hypothetical Commuter Rail
Part 2: At -Grade Crossing with Horn Blowing
Now consider the case of an active street crossing of the commuter railroad tracks. The General Noise Assessment method includes source reference levels for horns on moving trains and warning bells (crossing signals) at the street crossing. According to Table 4-9, the horn noise applies to track segments within '/a mile of the grade crossing.

Estimate Project Noise Exposure at 50 ft
Using the train volumes from Part I and the information in Table 4-9 and Table 4-I0, determine the day and nighttime Leq(Ihr) from sounding the horns at 50 ft.

Ld.LHorns
= SELYe f + 10 log(Vd) — 35.6
= 110 + 10log(2.8) — 35.6
= 78.9 dBA
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Ln.LHorns
= SELref + 101og(Vn) — 35.6
= 110 + 10log(0.7) — 35.6
= 72.9 dBA
Calculate the Ldn at 50 ft from train horns using Eq. 4-9 :

Ldn.LHorns
= 101og(15 x 10(LdLHorns/lo) + 9 x 10(<LnLHorns+io)/lo))_ 3.8 =81dBA
At -grade street crossings will have warning bells, typically sounding for 20 seconds for every train passby.

The total daytime and nighttime durations are as follows:

Ed
En
From Table 4-14:
= average daytime hourly duration
=20 seconds X 2.8 trains/hour = 56 seconds/hour
= average nighttime hourly duration
=20 seconds X 0.7 trains/hour = 14 seconds/hour
Ld.WBell
Ln.WBell
Ed
= SELref + 10 log(3600) - 35.6
56 = 109 + 10 log(3600) — 35.6
= 55.3 dBA
= SELref + 10log( 3600) - 35.6
14 = 109 + 10 log(3600) — 35.6
= 49.3 dBA
Calculate Ldn at 50 ft. from the warning bells using Eq. 4-17:

Ldn.WBell
= 101og(15 x 10(Ld.wBell/lo) + 9 x 10<<Ln.waeu+lo)/lo))_ 13.8 = 57.3 dBA
Compared to horn blowing, the crossing signal warning bell noise is negligible, but still must be included in the evaluation.

Estimate Existing Noise Exposure
From Part I, the existing noise level is 60 dBA.

Determine Noise Level and Distance for the Onset Of Impact As in Part I, the existing noise level (60 dBA) is used to determine the onset of moderate and severe impacts:

Existing
Noise
Ld.

Onset of Moderate
Impact
Ld.

Onset of Severe Impact
Ldp
60 dBA
58 dBA
64 dBA
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Determine the distance from the project noise sources to the impact contours using the fixed -guideway curve in Figure 4-6 (or the equations in Table 4-15) and the project impact thresholds obtained above. The project noise at 50 ft is approximately 81 dBA. However, there are at least two intervening rows of buildings, which will provide 6 dB (4.5 dB for the first row and 1.5 dB for the second row) of shielding.

Moderate impact (58 dBA)
58 — (81 — 6) = —17 dB
According to Figure 4-6, the distance correction is approximately -17 dB at 715 ft.

Severe Impact (64 dBA)
64—(81-6)= —11 dB
According to Figure 4-6, the distance correction is approximately -1 1 dB at 265 ft.

Project Level
Ld"
Onset of Moderate
Impact
Distance
Onset of Severe
Impact
Distance
81 dBA
715 ft
265 ft
Draw Noise Impact Contours
Contours can be drawn as in Part I for '/4 mile on either side of the grade crossing.

Example 4-2 General Noise Assessment — Highway/Transit
General Noise Assessment Example of Highway/Transit Corridor Projects This example illustrates a highway/transit project where the highway noise dominates and the FHWA assessment methods should be used to inform the FTA process according to the impact criteria in Section 4. I .

Case I: Highway Dominates
A new LRT system is planned for the median of a major highway that carries heavy traffic both day and night.

The noise levels at the first row of houses along the highway were measured during peak hour, mid -day and nighttime with hourly Leq(ih,) readings of 65 dBA, 63 dBA, and 60 dBA, respectively. The LRT tracks will be 125 ft from the first row of houses. The LRT operations during peak hour will be 4 -car trains at 45 mph, with 5 - minute headways in both directions. Nighttime service decreases to 2 -car trains and 20 minute headways.

FTA is providing a share of the funding for the LRT project, but the State DOT and the FHWA are co -lead agencies because the median requires considerable preparation for the tracks, including replacing bridge piers of street crossings and moving some highway lanes.

Assumptions
SELref = 82 dBA
Nd = 4 cars per train
Nn
S
Vd
V,
= 2 cars per train
= 45 mph
= 24 trains per hour
= 6 trains per hour
Estimate Project Noise Exposure at 50 ft
Use Table 4-9 and Table 4-10 to determine the peak hour Leq(ihr) for the rail vehicles.

Use Eq. 4-3 to calculate the LRT peak -hour noise level.

Ld.RCars (h)
= SELref + 10log (Ncars) + 201og( o) + 10log (V) — 35.6 45 = 82 + 10 109(4) + 201og(50) + 10 log(24) — 35.6
= 65 dBA at 50 ft
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Use Eq. 4-3 to calculate the LRT late evening hourly noise level.

Ln.RCars (h)
= SELref + 10 log(Ncars) + 201og(5) + 10 log(V) — 35.6
45 = 82 + 10 log(2) + 201og(50) + 10 log(6) — 35.6
= 56 dBA at 50 ft
Estimate Project Noise Exposure at 125 ft
Since the LRT tracks will be 125 ft from the first row of houses, use Figure 4-6 to determine the level at 125 ft.

At 125 ft, the distance correction is 5 dB.

Peak hour:
65 — 5 = 60 dBA at 125 ft
Night hourly:
56-5= 51dBAat125ft
In this case, the highway dominates the noise environment in the area both day and night, by 5 dB during peak hour and 9 dB at night. According to Section 4. I and Table 4-2, use the FHWA assessment methods.

Example 4-3 General Noise Assessment — BRT System
General Noise Assessment for a BRT System in an Existing Railroad Right -of -Way This example for a simple BRT project illustrates using the FTA procedures for a new BRT corridor planned in an existing abandoned railroad ROW.

Assumptions
SELref = 82 for buses
S = 25 mph
Vd = (344 buses) / (I 5 hours) = 22.9 buses per hour
Vn = (I I6 buses) / (9 hours) = 12.9 buses per hour
Estimate Project Noise Exposure
Use the information and equations in Table 4-12 to calculate the daytime and nighttime Leq(Ihr) at 50 ft.

Cs = 15 for buses
S
Ld.Bus = SELref + 10log (Vd) + Cs1og(50) - 35.6
25 = 82 + 10 log(22.9) + 15log(50) — 35.6
= 55 dBA at 50 ft
Ln.Bus
S
= SELref + 10 log(Vn) + Cslog(50) - 35.6
25 = 82 + 10 log(12.9) + 15log(50) — 35.6
= 53 dBA at 50 ft
Calculate Ldfl at 50 ft for the project using Eq. 4-13.

Lctn.Bus = 101og(15 x 10(Ld.BUS /10) + 9 x 10(<Ln.Bus+10)/10)) - 13.8 = 60 dBA at 50 ft
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Estimate Existing Noise Exposure
The surrounding area is residential with 2,500 people per square mile starting approximately 100 ft away from the proposed alignment. Determine the existing noise using Table 4-17.

Ldn = 50 dBA
Determine Noise Level and distance for the Onset of Impact Determine the noise level for the onset of moderate and severe impact using Figure 4-2 and the existing noise level of 50 dBA. Note that this project is land use category 2 and the appropriate metric is Ldn.

Existing
Noise
Ldn
Onset of Moderate Impact
Ldp
Onset of Severe
Impact
Ldn
50 dBA
54 dBA
59 dBA
Determine the distance to the noise impact contours using the fixed -guideway & highway curve in Figure 4-6 (or the equations in Table 4-15) and the project impact thresholds obtained above. The project noise level at 50 ft is approximately 60 dBA.

Moderate impact (54 dBA)
54 — 60 = —6 dB
According to Figure 4-6, the distance correction is approximately -6 dB at 125 ft.

Severe Impact (59 dBA)
59 — 60 = —1 dB
According to Figure 4-6, the distance correction is less than - I dB at approximately 60 ft.

Project Level
Ldn
Onset of Moderate
I m pact
Distance
Onset of Severe Impact
Distance
60 dBA
125 ft
60 ft
Inventory of Noise Impact
Since there are residential land uses approximately 100 ft away from the proposed alignment and the onset of moderate impact is at 125 ft, there are possible moderate impacts to the residences.

Noise Mitigation
A barrier is proposed for mitigation between the BRT system and the residences. The analysis is repeated and results in a predicted new project level of 55 dBA and the following impact distances:

Mitigated Project
Level
Ldn
Onset of Moderate
Impact
Distance
Onset of Severe Impact
Distance
55 dBA
60 ft
N/A
With a noise barrier in place between the BRT system and the residences, it is predicted that the onset of moderate impact would occur approximately 60 ft away from the BRT system. Since the residential area begins approximately 100 ft away from the BRT system, which is beyond the distance of moderate impact (60 ft), a noise barrier would provide the appropriate noise mitigation for the predicted moderate impact.

The onset of severe impact is listed as N/A because with a noise barrier, the severe impact criterion is not exceeded by the project.

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Example 4-4 General Noise Assessment — Transit Center
General Noise Assessment for a Transit Center
The following example illustrates the procedure for performing a General Noise Assessment for a stationary source. The example represents a typical FTA-assisted project in an urban area, the siting of a busy transit center in a mixed commercial and residential area, as shown in Figure 4-8.

Assume that the Noise Screening Procedure has already been done for this project and the nearest residence has been identified approximately 140 ft from the center of the proposed transit center. Recall that if any residential or other noise -sensitive land use is identified within 150 ft of a transit center during the Noise Screening Procedure, additional analysis is required.

Assumptions
■ Main Street Traffic
Peak hour traffic of 1200 autos, 20 heavy trucks, 300 medium trucks. • Population Density
12 houses per block, single family homes, 3 people per family. o Block area 78,750 square ft.
o Population density = 9,750 people/square mile.
■ Bus Traffic
Period
Hours
Buses per
Hour
Peak, Morning
7 a.m.-9 a.m.
30 Peak, Afternoon
4 p.m. -6 p.m.
30 Mid -day
9 a.m.-4 p.m.
15 Evening
6 p.m.—IO p.m.
12 Early Morning (Night)
6 a.m.-7 a.m.
15 Late Night
10 p.m. —I a.m.
4 Estimate Project Noise Exposure at 50 ft
Determine the hourly volume of buses during day and night.

Daytime (7 a.m. — 10 p.m.)
273 buses
15 hours
= 18.2 buses/hour
Nighttime (I0 p.m. — 7 a.m.)
27 buses
V" = = 3 buses/hour
9 hours
Calculate the daytime and nighttime Limh,-) at 50 ft for the bus transit center using the reference levels in Table 4-13 and the equations in Table 4-14.

Ld.BTCenter
Ln.BTCenter
=SELYef+CN-35.6

18.2 = 101 + 101og( 20 )-35.6
= 65 dBA at 50 ft
= SELref + CN - 35.6
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3 = 101 + 101og(20) — 35.6
ft = 57 dBA at 50
Calculate Ldh at 50 ft for the project using Eq. 4-17.

L = 1010 15 x 10�d
LBTCenter . /10) + 9 x 10<<LnBTCenter+10)/10) -13.8
dn.BTCenter g( )
= 66 dBA at 50 ft
Estimate Existing Noise Exposure
Estimate existing noise at noise -sensitive sites from the dominant noise source, and either major roadways or local streets (population density).

Roadway Noise Estimate — The traffic on Main Street qualifies this street for the Other Roadway category in Table 4-17. According to the map, the nearest residence is 275 ft from the edge of Main Street. The table shows existing Ldn = 55 dBA at this distance for representative busy city street traffic.

Population Density Noise Estimate — Noise from local streets is estimated from the population density of 9,750 people/square mile. Table 4-17 confirms that the Ldn is approximately 55 dBA.

In this example, the existing noise level by both the roadway and population density estimates are the same, but that is not always the case. If the levels are different, use the lower noise level. The existing noise level associated with the residential neighborhood in this example is Ldn = 55 dBA.

Determine Noise Level and Distance for the Onset of Impact Determine the noise level for the onset of moderate and severe impact using Figure 4-2 and the existing noise level of 55 dBA. Note that this project is land use category 2 and the appropriate metric is Ldn.

Existing Noise
Ldn
Onset of Moderate
Impact
Ldn
Onset of Severe
Impact
Ld.
55 dBA
56 dBA
62 dBA
Determine the distances from the center of the property to the noise impact contours using the stationary curve in Figure 4-6. The project noise level at 50 ft is 66 dBA.

Moderate impact (56 dBA)
56-66= —10 dB
According to Figure 4-6, the distance correction is approximately - I 0 dB at 125 ft.

Severe impact (62 dBA)
62 — 66 = —4 dB
According to Figure 4-6, the distance correction is -4 dB at approximately 70 ft.

Project Noise
Lei
Onset of Moderate
Impact
Distance
Onset of Severe
Impact
Distance
66 dBA
125 ft
70 ft
Draw Noise Impact Contours
Draw lines at 70 ft and 125 ft from the center of the property of the proposed transit center. These lines represent the noise impact contours. (Note that in Figure 4-8 the severe impact contour is not drawn for clarity. The contour is just within the dashed line representing the moderate impact contour after mitigation).

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Inventory of Noise Impact
Within, or touching, the contour defining moderate impact are three residential buildings (shaded in Figure 4-8). No residences are within the severe impact contour.

Noise Mitigation
The process is repeated with a hypothetical noise barrier at the property line on the residential side of the transit center. This would consist of a wall approximately 15 ft high partially enclosing the transit center, sufficient to screen the residences but not the commercial block facing Main Street. According to Table 4-14, the approximate noise barrier effect is -5 dB. Repeating the procedure above, the noise barrier will reduce the moderate impact contour to 80 ft and the severe impact contour to 45 ft (note that at 50 ft the distance correction is 0), which in this example eliminates all potential impacts on the residences.

IMPACTED RESIDENCES

SCALE IN FEET
200
400
Moderate Impac
Noise Contour
With Mitigation
Proposed
Transit Center
c -4--
Bus Parking
404
Moderate Impact
Noise Contour ,
without Mitigation
Figure 4-8 Example of Project for General Noise Assessment:

Siting of Transit Center in Mixed Commercial/Residential Area

4.5 Evaluate Impact: Detailed Noise Analysis
Evaluate for impact using the Detailed Noise Analysis procedure in this section, if appropriate. For guidelines on when the Detailed Noise Analysis is appropriate, review Section 4.2.

The steps in the Detailed Noise Analysis (Figure 4-9) parallel the steps in the General Noise Assessment, though the Detailed Noise Analysis employs equations for computations rather than graphs or tables. Each step in the Detailed Noise Analysis is more refined in the prediction of project noise and subsequent evaluation of mitigation measures. Noise projections from the project must be determined for each receiver.
• Step I: Identify Noise -Sensitive Receivers
Identify the noise -sensitive receivers of interest in the impact analysis study, including clustering noise -sensitive areas. This identification is usually based FEDERAL TRANSIT ADMINISTRATION 64

TRANSIT NOISE AND VIBRATION IMPACT ASSESSMENT MANUAL
on the Screening Procedure and General Noise Assessment previously conducted.
■ Step 2: Determine Project Noise Source Reference Levels Determine the project noise sources and reference levels. Then, estimate the project noise exposure at the reference distance of 50 ft, considering operational characteristics. When appropriate, measurements may be used to determine noise source reference levels.
■ Step 3: Determine Propagation Characteristics
Estimate project noise exposure as a function of distance, accounting for shielding and propagation along the path.
■ Step 4: Combine Noise Exposure from All Sources
Combine all sources to predict the total project noise at receivers. ■ Step 5: Determine Existing Noise Exposure
Determine the existing noise exposure. Measurements are used to determine the existing noise exposure. When measurements are unavailable, a simplified procedure to estimate existing noise exposure may be used with a clear justification to and approval by the FTA Regional office. ■ Step 6: Assess Noise Impact
Assess the noise impact at each receiver of interest using separate procedures for transit only and multimodal transportation projects. ■ Step 7: Determine Noise Mitigation Measures
Evaluate the need for mitigation and repeat the Detailed Noise Analysis with proposed mitigation.

When situations arise that are not explicitly covered in the Detailed Noise Analysis, professional judgment, in consultation with the FTA Regional office, may be used to extend these methods to cover these unique cases, when appropriate. Appendix G provides information on developing and using non- standard modeling procedures.

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Receiver of
Interest
Project
Sources
Operational Propagation
Characteristics Characteristics
Reference
SEL, 50 It
Ldn. 50 ft
Leg, 50 ft
Exposure vs
Distance
Cury
Project
Noise
Yes
Study Area
Characteristics
Noise Impac
Criteria
Noise
Impact
Mitigation
Required?
f emaining
Noise Impact
Figure 4-9 Procedure for Detailed Noise Analysis
Step I: Identify Noise -Sensitive Receivers
Select the noise -sensitive receivers of interest, the number of which will depend upon the land use in the vicinity of the proposed project and the extent of the study area defined by the Noise Screening Procedure in Section 4.3 and the results of the General Noise Assessment in Section 4.4.

The steps in identifying the noise -sensitive receivers of interest, both the number of receivers needed and their locations, shown in Figure 4-10, include:

I a. Identify all noise -sensitive land uses.

I b. Select individual receivers of interest.

I c. Cluster residential neighborhoods and other large noise -sensitive areas.

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Buildings
Used by Public
Identified Noise
Impacted Sites
Isolated
Residences
Select
Every Site
Small
Outdoor
Areas
Sources of
Land Use Information
Residential
Neighborhoods
Figure 4-10 Guide to Selecting Noise -Sensitive Receivers of Interest One Site
In Each
Cluster
Large
Outdoor
Areas
I a. Identify all noise -sensitive land uses where impact is identified by the General Noise Assessment in Section 4.4. If a General Noise Assessment has not been done, include all noise -sensitive sites according to the Noise Screening Procedure in Section 4.3. In areas where ambient noise is low, include land uses that are farther from the proposed project than for areas with higher ambient levels.

Recommended materials and methods that can assist in locating noise -sensitive land uses near the proposed project include:
• Land use maps prepared by regional or local planning agencies or by the project staff. Area -wide maps often do not have sufficient detail to be of much use. But they can provide broad guidance and may suggest residential pockets hidden within otherwise commercial zones. Of more use are project -specific maps that provide building -by -building detail on the land near the proposed project.
• Road and town maps can supplement other maps, are generally more up- to-date, and may be of larger scale.
■ Aerial photographs, when current, especially those of 400 -ft scale or better, are valuable in locating all potential noise -sensitive land uses close to the proposed project. In addition, they can be useful in determining the distances between receivers and the project.
• Windshield survey, in which the corridor is driven and land uses are annotated on base maps, may be used for definitive identification of noise - sensitive sites. The windshield survey, supplemented by footwork where needed, is especially useful in identifying newly -constructed sites and in confirming land uses very close to the proposed project. In addition, maps and aerial photos typically reveal only horizontal distances, not vertical distances. Houses on a hill overlooking the project may need a barrier of unacceptable height for its attenuation to be effective, and the greater vertical distance between source and receiver may eliminate the impact entirely. The windshield survey would reveal where vertical contour maps FEDERAL TRANSIT ADMINISTRATION 67

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or other means may be needed so that vertical distances can be determined.
■ Geographic Information Systems (GIS) provides electronic mapping needed for identifying noise -sensitive land uses. GIS data may include land parcels, building structures, aerial photography, and project -specific information. These data may be obtained during the project study or from local or regional agencies that store and maintain GIS data. Using electronic GIS data has advantages over paper mapping with respect to automating the process of identifying noise -sensitive land uses and accurately being able to determine their distances to the project alignment
Table 4-18 contains three types of land uses of interest and provides guidelines as to when receivers should be analyzed individually and when they can be clustered.

Table 4-I8 Land Uses of Interest
Land Uses
Specific Use
Selecting Receivers
Residences
Isolated single family residences
Neighborhoods (single and
multi -family residences,
apartment buildings, duplexes,
etc.)
Select each isolated residence as a receiver of interest.

For residential areas, cluster by proximity to project
sources, proximity to ambient -noise sources, and location along project line. Choose one receiver of interest
(closest to the project noise source and at an
intermediate distance from the predominant sources of
existing noise) in each cluster (i.e., Balance the distance between the receiver and the new noise source and the
receiver and the existing noise source). Multiple clusters in one location may be needed to fully characterize the area.

Indoor noise-
sensitive sites
Places of worship
Schools Hospitals/nursing
homes Libraries
Public meeting halls
Concert
halls/auditoriums/theaters
Recording/broadcast studios
Museums and certain historic
buildings
Hotels and motels
Other public buildings with
noise- sensitive indoor use
Select noise -sensitive buildings as separate receivers of interest.

Outdoor noise-
sensitive areas
Certain parks
Historic sites used for
interpretation
Amphitheaters
Passive recreation areas
Cemeteries
Other outdoor noise -sensitive
areas
For relatively small noise -sensitive areas, select noise - sensitive sites as separate receivers of interest.

For relatively large areas (e.g. a cemetery, etc.), cluster by proximity to project noise sources, proximity to ambient - noise sources, and location along project line. Choose one receiver of interest (closest to the project noise source and at an intermediate distance from the predominant
sources of existing noise) in each cluster.

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I b. Select the following types of noise -sensitive receivers within the noise study area, per Table 4-18, to be evaluated as individual receivers:
• Every major noise -sensitive public building
• Every isolated residence
• Every relatively small outdoor noise -sensitive area
Use judgment to avoid analyzing noise where such analysis is obviously not needed. Areas that are considered particularly noise -sensitive by the community, but do not meet the criteria in Table 4-3, should be considered on a case -by -case basis as discussed in Section 4. I.

I c. Residential neighborhoods and relatively large outdoor noise -sensitive areas can often be clustered, simplifying the analysis that is required without compromising the accuracy of the analysis. Subdivide all such neighborhoods/areas into clusters of approximately uniform noise, each containing a collection of noise -sensitive sites. Strive to obtain uniformity of both project noise and ambient noise using the following guidelines:
• In general, project noise reduces (drops off) with distance from the project.

For this reason, project noise uniformity requires nearly equal distances between the project noise source and all sites within the cluster. Clusters are typically shaped as long narrow strips parallel to the transit corridor and/or circling project point sources such as maintenance facilities. It is suggested to cluster sites where the project noise varies over a range of 5 dB or less.
• Note that noise drops off approximately 3 dB per doubling of distance for line sources and approximately 6 dB per doubling of distance for point sources over open terrain. This reduction in noise will occur over a shorter distance in areas containing obstacles blocking the path of sound propagation, such as rows of buildings.
• Ambient noise usually drops off from non -project sources in the same manner as noise from project sources. For this reason, clustering for uniform ambient noise will usually result in long narrow strips parallel to major roadways or circling major point sources of ambient noise, such as manufacturing facilities. It is suggested to cluster sites where the ambient noise varies over a range of 5 dB or less. Ambient noise levels may be difficult to judge without measurements. In areas without predominant sources of noise, like highways, ambient noise can be considered to vary with population density, which is often uniform along the corridor. In situations where ambient noise tends to be uniform, the clusters can encompass relatively large areas.

After defining clusters, select one representative receiver in each cluster. It is recommended to choose the receiver closest to the project noise source and at an intermediate distance from the predominant sources of existing noise. See Appendix D for additional guidance and examples on clustering receivers, as well as an example.

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Assess each identified cluster representative and individual noise -sensitive receiver of interest using the Detailed Noise Analysis as presented in the following steps.

Step 2: Determine Project Noise Source Reference Levels Identify the major project noise sources near the noise -sensitive receivers of interest, group them by source type, and determine reference levels to compute project noise at SO ft, as shown in Figure 4-1 I.

Receivers of
Interest
Fixed -guideway
Sources
Separate Sources
by Source Type
HighwayiTransit
Sources
Determine
(SEL) ref
Convert to
Ldn andlor Leq
at 50 ft.

Project noise
Sources
Stationary
Sources
Figure 4-I I Flow Diagram for Determining Project Noise at 50 ft 2a. Identify the major project noise sources near receivers of interest according to Table 4-19. The right-hand column of the table indicates if each source is considered as a major contributor to the overall noise impact. Note that some noise sources can create high noise levels but are not indicated as major contributors. Although such sources are loud, they rarely stay in a neighborhood for more than a day or two; therefore, the overall noise exposure is relatively minor. Computations are required for all major noise sources in this table.

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Table 4-19 Sources of Transit Noise
Project Type
Source Type
Actual Source
Major?
Commuter Rail
Light Rail Streetcars
RRT
Fixed -Guideway
Locomotive and rail car passbys
Horns and whistles
Crossing signals
Crossovers/switches
Squeal on tight curves
Track -maintenance equipment
Yes
Yes
Yes
Yes
Yes
No
Stationary
Substations
Chiller plants
Yes
No
Busways
Bus Transit Malls
Highway/Transit
Bus passbys
Buses parking
Yes
No
Stationary
Buses idling
Yes
AGT
Monorail
Fixed -Guideway
Vehicle passbys
Yes
Miscellaneous
Line equipment
No
Terminals
Stations
Transit Centers
Fixed -Guideway
Locomotive and rail car passbys
Crossovers/switches
Squeal on tight curves
Yes
Yes
Yes
Highway/Transit
Bus passbys
Buses parking
Automobile passbys
Yes
No
No
Stationary
Locomotives idling
Buses idling
Ferry boats landing, idling, and departing at dock
HVAC equipment
Cooling towers
P/A systems
Yes
Yes
Yes
No
No
No
Park -and -Ride Lots
Highway/Transit
Bus passbys
Buses idling
Automobile passbys
Yes
Yes
No
Stationary
P/A systems
No
Traffic Diversion Projects
Highway/Transit
Highway vehicle passbys
Yes
Storage Facilities
Maintenance Facilities
Fixed -Guideway
Locomotive and rail car passbys
Locomotives idling
Squeal on tight curves
Horns, warning signals, coupling/ uncoupling,
auxiliary equipment, crossovers/ switches, brake
squeal, and air release
Yes
Yes
Yes
Yes
Highway/Transit
Bus passbys
Yes
Stationary
Buses idling
Yard/shop activities
Car washes
HVAC Equipment
P/A Systems
Yes
No
No
No
No
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2b. Separate the major noise sources by source type: fixed -guideway transit, highway/transit or stationary facility. Note that a major fixed -guideway system will usually have stationary facilities associated with it, and that a stationary facility may have highway/transit elements associated with it. Then use the instructions in the following source type options below to:
2c. Determine the source reference levels for the all project noise sources.

Each source reference level pertains to reference operating conditions for stationary sources or one vehicle passby under reference operating conditions.

These reference levels should incorporate source -noise mitigation only if such mitigation will be considered for incorporation into the system specifications.

The source levels used in this manual are typical of systems designed according to current engineering practice, but they do not include special noise control features that could be incorporated in the specifications at extra cost. If special features that result in noise reductions are included in any of the predictions, the Federal environmental documents must include a commitment by the project sponsor to adopt such treatments before the project is approved for construction. For example, if the specifications include vehicle noise limits that may not be exceeded, these limits should be used to determine the reference level, and this level should be used in the analysis rather than the standard, tabulated reference level.
2d. Convert the source reference level to noise exposure in terms of Leq(Ihr) or La" under project operating conditions using the appropriate equations depending upon the type of source. The noise exposure is determined at the reference distance of 50 ft.

Option A. Fixed -guideway Sources — Compute project noise at 50 ft for fixed -guideway sources as identified in the second column of Table 4-19.

A.i. Reference SEL Levels
Determine the reference SEL at 50 ft for each major fixed -guideway noise source, either by measurement according to Appendix F or by referencing Table 4-20. The table provides guidance on which method is preferred for each source type. The "NO" designation implies that the source levels given in the table are appropriate to use in the analysis, and the "YES" designation implies that measurements are preferred over the data given in the table. In general, measurements are preferred for source types that vary considerably from project to project, including any emerging technology sources. The data in the table are adequate for source types that do not vary considerably from project to project.

For sources where measurements are preferred, refer to Appendix F for guidance on measurement procedures and methods for conversion of these measurements to the reference conditions of Table 4-20. For projects where source -noise specifications have been defined (e.g., noise limits are usually included in the specifications for purchase of new transit vehicles), these specifications may be used instead of measurements after conversion to reference conditions using the equations in Appendix F. This is only appropriate when there is a firm commitment to adopt the noise specifications in the vehicle FEDERAL TRANSIT ADMINISTRATION 72

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procurement documents during the engineering phase and to adhere to the specifications throughout the procurement, delivery, and testing of the vehicles.

Approximate L. values are provided in the table for general user information.

As discussed in Appendix B.I.4.2, Lm,, is not used directly in the evaluation of noise impact.

Table 4-20 Source Reference SELs at 50 ft: Fixed -Guideway Sources at 50 mph Source
Reference
SEL, dBA
Approximate
Lrr,ax, dBA
Prefer
Measurements? *
Rail cars
82 80
No
Streetcars**
76 74
No
Locomotives — diesel
92 88
No
Locomotives — electric
90 86
No
Diesel multiple unit (DMU)
85 81
Yes
Agt — steel wheel
80 78
Yes
Agt — rubber tire
78 75
Yes
Monorail
82 80
Yes
Maglev
72 70
Yes
Transit car horns (emergency)
93 90
No
Transit car whistles
81 78
No
Locomotive horns
At -grade crossing
113
I I O
No
From crossing to 1/8 mile
t
I I O
From 1/8 mile to 1/4 mile
110
110
* "No" implies that the source levels given in the table are appropriate to use in the analysis and "Yes" implies that measurements are preferred over the data given in the table. **The reference speed for streetcars is 25 mph. For streetcar speeds above 25 mph, use the "Rail Cars" reference level and 50 mph for the reference speed. t Use the following equation for locomotive horns from crossing to I /8 mile:

SELRef = 113-3 x (°p)
660
where:

Dp= distance from grade crossing parallel to tracks
A.ii. Estimate Noise Exposure at 50 ft — Use the reference SELs in Table 4-20, operating conditions, and the equations in Table 4-21 to predict the noise exposure at 50 ft expressed in terms of Lego nro and Ldn. Follow the steps below:

I. Identify operating conditions — Trains with different numbers of cars or operating conditions produce different noise exposure levels and should be converted from SEL to Ldn separately. Use the following guidelines to determine if sources should be converted separately. These differences in operating conditions will produce an approximate 2 -decibel change in noise exposure:
• 40 percent change in number of locomotives or cars per train. • 40 percent change in number of trains per hour.
• 40 percent change in number of trains per day, or per night (for computation of Ldn).
• 15 percent change in train speed.
• Change of one notch in diesel locomotive throttle setting (e.g., from notch 5 to notch 6).

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2. Establish relevant time periods — For each of these source types and conditions, determine the relevant time periods for all receivers that may be affected by this source.
• For residential receivers, the time periods of interest for computation of Ldn are: daytime (7 a.m. to 10 p.m.) and nighttime (I 0 p.m. to 7 a.m.).
• If the source will affect non-residential receivers, the time period of interest is the loudest hour of project -related activity during hours of noise sensitivity. Several different hours may be of interest for non-residential receivers depending on the hours the facility is used.

3. Collect input data
• Source reference SELs for locomotives, rail cars, and warning horns. • Number of rail cars in the train (if this number varies during the day, take the average for the daytime and nighttime periods separately for category 2 land uses, and use the maximum number during the period of interest for category I or 3 land uses). • Number of locomotives in the train, if any.
• Train speed, in miles per hour (maximum expected).
• Average throttle setting of the train's locomotive(s) for diesel - powered locomotives and DMU's only.( ) If this input is not available, assume a throttle setting of 8 for locations where the vehicle would accelerate and 5 for all other Iocations.(25) • For residential receivers of interest:
• Average hourly train volume during daytime hours (the total number of train passbys between 7 a.m. and I O p.m., divided by I5 hours);
• Average hourly train volume during nighttime hours (the total number of train passbys between I O p.m. and 7 a.m., divided by 9 hours);
• For non-residential receivers of interest, number of events that occur during each hour of interest in trains per hour; and • Track type (continuously welded or jointed) and profile (at -grade or elevated).

4. Calculate Leq(Ihr) at 50 ft
• Calculate Leq(Ihr) using the appropriate equations in Table 4-21 for each hour of interest.
• Compute the combined Leq(Ihr). It may be necessary to compute the combined totals with and without the warning horns; some neighborhoods along the corridor may be exposed to the horn noise and some may not.

5. Calculate Ldn at 50 ft
• If the project noise will affect any residential receivers, calculate the Ldn using the combined day Leq(Ihr) and the combined night Leq(Ihr). • It may be necessary to calculate Ldn with and without the warning horns, as above.
iv Omit this term if not applicable from the equation in Table 4-2 I for other vehicle types.

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Note that the equations in Table 4-2I include terms to account for a difference in speed from the reference speed of 50 mph and a numerical adjustment to account for the one -hour time period for this metric. For more information on the numerical adjustment to represent the time period of interest, see Appendix B.I.4.4.

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Table 4-2 I Computation of Leq(Ihr) and Ldn at 50 ft: Fixed -Guideway Sources Locomotives*
Leq(Ihr)at 50 ft
S Eq. 4-25
Leq.Loco(1hr) = SELref + 10 log(NLoco) + CT + Klog(50) + 10 log(V) — 35.6 Locomotive
Warning
Horns**
Leq(Ihr)at 50 ft
o V Eq. 4-26
Leq.LHorns(lhr) = SEL ref + 10 log(V) — 35.6
Rail Vehiclest
Leq(Ihr)at 50 ft
S
Leq.Rcars(lhr) = SELYef + 1O 1og(Ncars) + 201og(50) + 10 log(V) — 35.6 Eq. 4-27 + Adjtrack
Streetcar
(25 mph or slower)
Leq(Ihr)at 50 ft
Legscars(1hr) = SELTef + 10 log(Ncars) + 2Iog(25) + 10 log(V) — 35.6 + Adjtrack Eq. 4-28 Transit
Warning
HoHorns** eq.THorns(lhr)
Leq(Ihr)at 50 ft
L S V 35.6 Eq. 4-29
= SEG ref — 10 log + 10 log )
Combined
Locomotive and
transittt
Leq(Ihr)at 50 ft
Leq.Loco(1hr) Leq.Rcars(ihr)X10)
Leq.Combo(lhr) = 101og(L 0( X10) + i0( Eq. 4-30
eq.SCars(lhr) eq.LHorns(1hr) eq.THorns(1hr)
+ 10( /10) + 10( /10) + 10(L /10)
Daytime
La at 50 ft

Ld = Leq(lhr) where V = Vd, NLoco = Nd (loco events), and Ncars = Nd (car events) Eq. 4-3 I Nighttime
Gat 50 ft
Ln = Leq(lhr) where V = Vn, and NLoco = Nd (loco events), and Ncars = Nd (car Eq. 4-32 events)
Day/NightLan 500ft Gan
= 101og(15 X 10(Ld'lo) + 9 X 10((Ln+10) 10)) - 13.8 Eq. 4-33 = average number of locomotives per train
NLoco
CT =OforT www.fra.dot.gov/Elib/Document/268 I
t Includes all commuter rail cars, transit cars, streetcars above 25 mph, AGT and monorail. tt Only include appropriate terms. { Because of the wide range of vehicle types that qualify as a DMU, measurements are preferred for the reference level and speed coefficient. If no measurements are conducted, use the reference level in Table 4-20 and a speed coefficient of 0.

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Example 4-5 Detailed Noise Analysis — Fixed Guideway Noise Sources Computation of Leq(Ihr) and Ldn at 50 ft for Fixed -Guideway Source A commuter train with I diesel locomotive and 6 cars will pass close to a residential area at a grade crossing.

The track is jointed.

Assumptions
SELref
NCars
NLoco
S
T
Vd
Vn
= 92 for diesel locomotives
= 82 for rail cars
= 113 for locomotive warning horns at -grade crossing
=6
1 = 43 mph
=8
= 40 trains/15 hours = 2.667 trains per hour
= 2 trains/9 hours = 0.222 trains per hour
Use the equations in Table 4-2I to determine the daytime Leq(Ihr) for each source and the combined daytime Leq(Ihr) at 50 ft.

Ld.Locs(lhr)
Ld.RCars(lhr)
Ld.LHorn(ihr)
Ld.Combo(1hr)
With horn:

Without horn:

S
= SELref + 101og(NLoco) + CT + Klog(50) + 10 log(Vd) — 35.6 43 = 92 + 10 109(1) + 6 + (-10)log(50) + 10 log(2.667) — 35.6 = 67.3 dBA at 50 ft
= SELref + 10 log(Ncars) + 201og (50) + 10 log(Vd) — 35.6 + Adjtrack 43 = 82 + 10 log(6) + 201og (50) + 10 log(2.667) — 35.6 + 5 = 62.1 dBA at 50 ft
= SELref + 10 log(Vd) — 35.6
= 113 + 10 log(2.667) — 35.6
= 81.7 dBA at 50 ft
= 10log [10
= 81.9 dBA in neighborhoods where the horn is sounded
(Ld.Locos(ihr)/10) 10 1(Ld.RCars(ihr)/ 0 ) 10 (Ld.LHorn(lhr)/ 10) ++
= 101og [10(Ld.Locos(ihr)/10) + 10(Ld.RCars(ihr)/10)1
= 68.4 dBA in neighborhoods where the horn is not sounded Use the same equations as above to determine the nighttime Leq(Ihr) at 50 ft. Use Vn instead of Vd.

Ln.Locos(1hr)
Ln.RCars (1 hr)
Ln.LHorn(lhr)
Ln.Combo(1hr)
= 56.5 for locomotives
= 51.3 for cars
= 70.9 for horns
=71.1 in neighborhoods where the horn is sounded
= 57.6 in neighborhoods where the horn is not sounded
Calculate the Ldn with and without horns.

Ldn.combo = 10log [15 x 10(Ld.Combo/lo) + 9 x 10((Ln.combo+lo)'l°) — 13.8
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With horn: = 81.6 at 50 ft in neighborhoods where horns are sounded Without horn: = 68.1 at 50 ft in neighborhoods where horns are not sounded Note: Computation results should always be rounded to the nearest decibel at the end of the computation. In all examples of this section, however, the first decimal place is retained for readers to precisely match their own computations against the example computations.

Option B. Highway/Transit Sources — Compute project noise at 50 ft for highway/transit noise sources as identified in the second column of Table 4-19.

Use the instructions below to estimate source noise levels for projects following FTA's procedures that involve highway vehicles.

This method is based on the original FHWA highway noise prediction model, with updated noise emission levels.(26) The vehicle equations are applicable to speeds typical of freely -flowing traffic on city streets and access roads.

B.i. Reference SEL Levels — Determine the reference SEL at 50 ft for each major highway/transit source, either by measurement according to Appendix F or by using Table 4-22.(x) The table provides guidance on which method is preferred for each source type. "NO" implies that the source levels given in the table are appropriate to use in the analysis, and "YES" implies that measurements are preferred over the data given in the table. For sources where measurements are preferred, refer to Appendix F for guidance on measurement procedures and methods for conversion of measurement data to the reference conditions in Table 4-20.

Approximate Lmaxvalues are provided in the table for general user information.

As discussed in Appendix B.I.4.2, Lmax is not used directly in the evaluation of noise impact.

Table 4-22 Source Reference SELs at 50 ft: Highway/Transit Sources at 50 mph Source
Reference
SEL, dBA
Approximate
Lmax, dBA
Prefer
Measurements?*
Automobiles
74 70
No
Buses (diesel)
82 79
No
Buses (electric trolleybus)
80 77
No
Buses (hybrid)**
83 80
Yes
*"No" implies that the source levels given in the table are appropriate to use in the analysis and "Yes" implies that measurements are preferred over the data given in the table. ** Hybrid bus with full-time diesel engine and electric drive motors.

Idling buses are considered stationary sources.

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B.ii. Noise Exposure at 50 ft — Use the reference SELs in Table 4-22, operating conditions, and the equations in Table 4-23 to predict the noise exposure at 50 ft expressed in terms of Leq(Ihr) and Ldn. Follow the steps below:

I. Identify operating conditions — Noise emission from most transit buses is not dependent upon whether the buses are accelerating or cruising.

However, accelerating suburban buses are substantially louder than cruising suburban buses. For this reason, suburban buses require separate calculation along roadway stretches where they are accelerating. Separate calculation is also needed for all highway/transit vehicles at different speeds, since speed affects noise emissions. Use the following guidelines to determine if sources should be calculated separately. These differences in operating conditions will produce an approximate 2 -decibel change in noise exposure:
• 40 percent change in number of vehicles per hour;
• 40 percent change in number of vehicles per day, or per night (for computation of Ldn); or
• 15 percent change in vehicle speed.

2. Establish relevant time periods — For each of these source types and conditions, determine the relevant time periods for all receivers that may be affected by this source.
• For residential receivers, the time periods of interest for computation of Ldn are: daytime (7 a.m. to I O p.m.) and nighttime (I 0 p.m. to 7 a.m.).
• If the source will affect non-residential receivers, the time period of interest is the loudest hour of project related activity during hours of noise sensitivity. Several different hours may be of interest for non-residential receivers depending on the hours the facility is used.

3. Collect input data
• Source reference SELs for the vehicle types of concern • Average running speed in miles per hour
• For residential receivers of interest:
• Average hourly vehicle volume during daytime hours (total number of vehicle passbys between 7 a.m. and I O p.m., divided by 15).
• Average hourly vehicle volume during nighttime hours (total number of vehicle passbys between I O p.m. and 7 a.m., divided by 9).
• For non-residential receivers of interest, number of events that occur during each hour of interest, in vehicles per hour

4. Calculate Leq(Ihr) at 50 ft — Calculate Leq(Ihr) using the appropriate equations in Table 4-23 for each hour of interest.

5. Calculate Ldn at 50 ft — If the project noise will affect any residential receivers, calculate the Ldn using the day Leq(Ihr) and night Leq(Ihr).

Note that the equations in Table 4-23 include terms to account for a difference in speed from the reference speed of 50 mph and a numerical adjustment to FEDERAL TRANSIT ADMINISTRATION 79

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account for the one -hour time period for this metric. For more information on the numerical adjustment to represent the time period of interest, see Appendix B. I.4.4.

Table 4-23 Computation of Leq(Ihr) and Lan at 50 ft: Highway/Transit Sources Leq(Ihr) at 50
ft
L SELref + 10 log(V) + C — 1010 S 35.6
eq(1hr) = 9� ) emissions g�50)
Eq. 4-34
Daytime
La at50ft
Ld = Leq(ihr where V = Vd
)
Eq. 4-35
N
L� at 50 ft
Ln at 50 ft
Ln = Leq(lhr) where V = V� Eq.
4-36
Ld„ at 50 ft
Ldn = 101og(15 x 10(Ld/10) + 9 x 10((Ln+10)�10)) - 13.8 Eq. 4-37
Adjustments
= -3 for automobiles, open -graded asphalt
= +3 for automobiles, grooved pavement
V
Cemissions
S
Vd
V,
= average hourly volume of vehicles, vehicles per hour
= 2510g(so) for buses
311og(So) for hybrid buses (23)

1.6 for accelerating 3 -axle commuter buses
401og(So) for automobiles
= average vehicle speed, mph (distance divided by time, excluding stop time at red lights)
= average hourly daytime volume of vehicles of this type, vehicles per hour total vehicle volume, 7 a.m. to 10 p. m.
15 = average hourly nighttime volume of vehicles, vehicles per hour total vehicle volume,10 p. m. to 7 a.m.
9 Example 4-6 Detailed Noise Analysis — Highway Transit Noise Sources Computation of Leq(Ihr) and La. at 50 ft for Highway/Transit Source A bus route with city buses will pass close to a school that is in session from 8 a.m. to 4 p.m. on weekdays.

Within this time period, the hour of greatest activity for this bus route is 8 a.m. to 9 a.m.

Assumptions
SELref = 82 dBA
S =40mph
V = 30 buses per hour
Use the equations in Table 4-23 to determine the hourly Leq(Ihr) at 50 ft.

Ld.Bus
S
= SELref + 10 log(V) + Cemissions — 101og(50) - 35.6
40 40
= 82 + 10 log(30) + 6 + 25 x log(50) - 101og(50) — 35.6 = 59.7 dBA at 50 ft
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This same bus also passes close to a residential area with the following operating conditions:

Vd = 200 buses/15 hours = 13.33 buses per hour
Vu = 20 buses/9 hours = 2.22 buses per hour
Calculate the daytime and nighttime Leq(Inr) at 50 ft.
40 40
Gd.Bus = 82 + 10 log(13.33) + 6 + 25 x log(—)— 101og(50) — 35.6 = 56.2 dBA at 50 ft
40 40
Ln.Bus = 82 + 10 log(2.22) + 6 + 25 x log(0) — 101og(50) — 35.6 = 48.4 dBA at 50 ft
Calculate Ldp at 50 ft.

Gdn.Bus = 10log(15 x 10(LdBus/10) + 9 x 10((LnBus+1o)/10)) - 13.8 = 57.2 dBA at 50 ft
Note: Computation results should always be rounded to the nearest decibel at the end of the computation. In all examples of this section, however, the first decimal place is retained for readers to precisely match their own computations against the example computations.

Option C. Stationary Sources — Compute project noise at 50 ft for stationary sources as identified in the second column of Table 4-19.

C.i. Determine Reference SEL Levels — Determine the reference SEL at 50 ft for each major stationary source, either by measurement according to Appendix F or by using Table 4-24. The table provides guidance on which method is preferred for each source type. "NO" implies that the source levels given in the table are appropriate to use in the analysis, and "YES" implies that measurements are preferred over the data given in the table. In general, measurements are preferred for source types that vary considerably from project to project. For example, curve squeal is highly variable depending on weather conditions, curve radius, and train speed. The data in the table are adequate for source types that do not vary considerably from project to project (crossing signals, for example). For sources where measurements are preferred, refer to Appendix F for guidance on measurement procedures and methods for conversion of these measurements to the reference conditions of Table 4-24.

Layover facilities and transit centers can be the sources of low -frequency noise from idling diesel engines. Sounds with considerable low -frequency components can cause greater annoyance than would be expected based on their A - weighted levels. Low -frequency sounds often cause windows and walls to vibrate resulting in secondary effects in buildings such as rattling of dishes in cupboards and wall -mounted pictures. The reference levels in Table 4-24 are adjusted to take increased annoyance into account. For a Detailed Noise Analysis at locations where such idling takes place for an extended period, use the method described in ANSI Standard S I 2.9 -Part 4, Annex D.(27) Approximate Lmax values are provided in the table for general user information.

As discussed in Appendix B. I.4.2, Lmax is not used directly in the evaluation of noise impact.

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Table 4-24 Source Reference SELs at 50 ft: Stationary Sources Source
Reference
SEL, dBA
Approximate
L,„ , dBA
Prefer
Measurements?*
Auxiliary Equipment
I0I
65 Yes
Locomotive Idling
109
73 No
Rail Transit Idling
106
70 No
Buses Idling
I I I
75 No
Ferry Boat Landing**, Idling, and Departing
91 78
No
Ferry Boat Fog Horn
90 84
No
Track Curve Squeal
136
100
Yes
Car Washes
I I I
75 Yes
Crossing Signals
109
73 No
Substations
99 63
No
* "No" implies that the source levels given in the table are appropriate to use in the analysis, and "YES" implies that measurements are preferred over the data given in the table. **Ferry boat landings are included in the stationary source category because the noise from the landing remains in one area even though the boats move in and out.

C.ii. Estimate Noise Exposure at 50 ft — Use the reference SELs in Table 4-24, operating conditions, and the equations in Table 4-25 to predict the noise exposure at 50 ft expressed in terms of Leq(Ihr) and Ldn. Follow the steps below:

I. Identify operating conditions — Identify actual source durations and numbers of events. Sources with different operating conditions should be converted from SEL to Ldn separately. Use the following guidelines to determine if sources should be converted separately. These differences in operating conditions will produce an approximate 2 -dB change in noise exposure:
• 40 percent change in event duration (e.g., from 30 to 42 minutes), or
• 40 percent change in number of events per hour (e.g., from I O to I4 events per hour).

2. Establish relevant time periods — For each of these source types and conditions, determine the relevant time periods for all receivers that may be affected by this source.
• For residential receivers, the time periods of interest for computation of Ldn are: daytime (7 a.m. to 10 p.m.) and nighttime (I 0 p.m. to 7 a.m.).
• If the source will affect non-residential receivers, the time period of interest is the loudest hour of project related activity during hours of noise sensitivity. Several different hours may be of interest for non-residential receivers depending on the hours the facility is used.

3. Collect input data
• Source reference SELs for each relevant source
• Average duration of one event, in seconds
• For residential receivers of interest:

Average number of events per hour that occur during the daytime (the total number of events between 7 a.m. and I O p.m., divided by 15).

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• Average number of events per hour that occur during the nighttime (the total number of events between I0 p.m. and 7 a.m., divided by 9).
■ For non-residential receivers of interest, number of events that occur during each hour of interest in events per hour

4. Calculate Leq(Ihr) at 50 ft — Calculate Leq(Ihr) using the appropriate equations in Table 4-25 for each hour of interest.

5. Calculate Ldn at 50 ft — If the project noise will affect any residential receivers, calculate the Ldn using the day Leq(Ihr) and night Leq(Ihr).

Note that the equations in Table 4-25 include a numerical adjustment to account for the one -hour time period for this metric. For more information on the numerical adjustment to represent the time period of interest, see Appendix B. I.4.4.

Table 4-25 Computation of Leq(Ihr) and Ldn at 50 ft: Stationary Sources Leq(Ihr) at 50
ft
E 35.6
L+ log(N) +
Lea = SELref 10 t ) 101
Eq. 4-38
9( o g(3600)
Daytime
Ld at 50 ft
Ld = Leq(ihr where N = Nd
)
Eq. 4-39
Nighttime
L„ at 50 ft
Ln = Leq(1hr) where N = Nn
Eq. 4-40
Ldp at 50 ft
Ldn = 101og(15 x 10�Ldh o� + 9 x 10( in)) _ 13.8
Eq. 4-41
N
E*
Nd
N,
= number of events of this type that occur during one -hour = duration of one event, sec
= average hourly number of events that occur during daytime (7 a.m. to 10 p.m.)
number of events between 7 a. m. to 10 p.m.
15 = average hourly number of events that occur during nighttime (10 p.m. to 7 a.m.)
number of events between 10 p.m. to 7 a. m.
9 *Omit the term containing E for ferry boat, and fog horn noise sources.

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Example 4-7 Detailed Noise Analysis — Stationary Noise Sources Computation of Leq('hr) and Ldn at 50 ft for Stationary Sources A signal crossing lies close to a school that is in session from 8 a.m. to 4 p.m. on weekdays. Within this time period, the hour of greatest activity for the signal crossing is 8 a.m. to 9 a.m.

Assumptions
SELre f = 109 dBA
E = 25 seconds (counting both cycles of the signal)
N = 22
Use the equations in Table 4-25 to determine the hourly Leq(,hr) at 50 ft. = SEL + 10lo N E
L
dCross ref g( ) + 101og (3600/ 35.6
25 = 109 + 10log(22) + 10log(3600) 35.6
= 65.2 dBA at 50 ft
This same signal crossing lies close to a residential area with the following operating conditions:

Nd
Nn
= 200 /15 hours = 13.3 events per hour
=12 /9 hours = 1.33 events per hour
Calculate the daytime and nighttime Leq(,hr) at 50 ft.

Ld.Cross
Ln.Cross
25 = 109 + 10log(13.3) + 10log(3600) — 35.6
= 63.1 dBA at 50 ft
25 = 109 + 10log(1.33) + 10log(3600) — 35.6
= 53.1 dBA at 50 ft
Calculate Ldh at 50 ft.

Ldn = 10log(15 x 10(LdCross/lo) + 9 x 10((Lncross+10)/io)) — 13.8 = 63.1 dBA at 50 ft
Note: Computation results should always be rounded to the nearest decibel at the end of the computation. In all examples of this section, however, the first decimal place is retained for readers to precisely match their own computations against the example computations.

Step 3: Determine Propagation Characteristics
Determine the combined propagation characteristics between each source and receiver of interest.
3a. Calculate project noise exposure as a function of distance. Calculate the project noise exposure at distances other than 50 ft, such as at receiver locations, as a function of distance accounting for shielding and ground effects along the path. See Example 4-8 below.

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1. Determine the topography of the ground within the transit corridor using the figures in Table 4-26 as a guide. It is not necessary to represent the transit corridor with an extreme number of changes in topography. Often, several typical sections will suffice throughout the transit corridor.

2. Use the equations in Table 4-26 to determine ground factor (G) based on the effective path height (Neff) for each identified terrain feature. Standard source heights are included at the bottom of the table. Assume receiver heights of 5 ft for both outdoor receivers and first -floor receivers. Note that larger ground factors correspond to larger amounts of ground attenuation with increasing distance from the source. For acoustically "hard" (e.g., non -absorptive) ground conditions, G should be taken to be zero.

3. Determine the distance correction factor using the ground factor and another distance, such as the distance to a receiver, and the equations in Table 4-27.

4. Apply the distance correction (Cdistance) to the project noise exposure at 50 ft (Section 4.5, Step 2) using the following equation:

Ldistance
L5oft
Ldistance = L5oft + Cdistance
where:
= Ldn or LAeq(lhr) at the new distance, ft
= Ldn or LAeq(lhr) at 50 ft

5. Plot noise exposure as a function of distance if desired.

Eq. 4-42
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Table 4-26 Ground Factor G, for Ground Attenuation
Ground Factor
Soft Ground: 0.66,
Heff —
2 A
. B_FI
HS+Hc+Hr
Heff for Hb ≤ He
•-- )))Hb
Hr
Ill
— 2
H4 ,,
Het
Hs + 2Hb — He + Hr
Hb > He
Heff — for
Figure 4-14 Elevated Receiver
2 t
Use Eq. 4-44 forA ≤ B
Hb illi
•)D}
•
Hr
2 H4
NC
Hs + 2Hb + He + Hr B
Heff A>
Figure 4-15 Source
�/�{
in
Sloped Cut
= 2 for
2 e
•
- HS + Hr B
Heff = A≤2
H •DD) If
Hi 2 for
H❑
• Hs+2Hc+Hr B
Heff
A ►
= 2 for >
Figure 4-16 Source and Receiver Separated by Trench
HS = 8 ft for trains with diesel-electric locomotives = 3 ft for 2 -axle city buses = 2 ft for trains without diesel-electric locomotives = 8 ft for 3 -axle commuter buses = 0 ft for automobiles
Note: Equations for Heff remain valid when Hb = 0
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Table 4-27 Distance Correction Factor Equations for Detailed Noise Analysis Source
Equation*
Stationary Sources
Cdistance =—201og(D) — 10Glog(D)
50 50
Eq. 4-45
Fixed guideway rail car passbys
Cdistance =—101og(D) — 10Glog(D)
50 42
Eq. 4-46
Fixed -guideway locomotive and rubber -
tired vehicle passbys, highway vehicle
passbys and horns
Cdistance =—101og(D ) — 10Glog(D )
50 29
Eq. 4-47
D = distance, ft
G = ground factor, see Table 4-26
*These equations assume the distance between the source and receiver is approximately 300 ft or less. At longer distances, ground effects have an upper limit and atmospheric conditions may affect propagation characteristics. Therefore, more detailed calculation methods may be required to account for those effects.

Example 4-8: Detailed Noise Analysis — Exposure vs. Distance Curve Exposure vs. Distance Curve for Fixed -Guideway Source
Plot an exposure vs. distance curve for a diesel-electric commuter train that does not sound the horn in this area.

Assumptions
The terrain is flat grassland without a noise barrier.

Leq.Loco (8 — 9am)
Ldn.Loco
Hr
Hb
HS
= 72 dBA at 50 ft
= 68 dBA at 50 ft
=5ft
= 0 ft (for a "no noise barrier" case)
= 8 ft (for a diesel-electric commuter train)
Calculate Heff using the equations in Table 4-26.

HS + 2Hb + Hr
Heff =
2 8+0+5
2 = 6.5 ft
Determine the ground factor using Eq. 4-43.
f
G =0.75(1- 42f)
= 0.63
Use Eq. 4-45 to determine noise vs. exposure equations for Ld.loco and Lan,..

Leq.Loco = 72 — 101og( °S) — 6.31og(°42)
Ldn.Loco = 68 — 101og(° SO) — 6.31og( ° )
42 Plot the two equations (see example in Figure 4-17). From these curves, the noise levels due to this train operation can be determined for a receiver of interest at any distance without shielding.

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3b. Calculate the attenuation due to shielding for each distance of interest from Step 3a, using the following equation and Tables 4-26 through 4-30 and as illustrated in Example 4-9. If the conditions described in the tables are not met, the attenuation due to shielding is considered zero. Shielding can be due to intervening noise barriers, terrain features, rows of buildings, and dense tree zones.

Ashielding = maxt/Lbarrier or Abuildings or Atrees)
where:

ILbarrier = barrier insertion loss, see Table 4-28
Abuildings
Atrees
= attenuation due to buildings, see Table 4-29
= attenuation due to trees, see Table 4-30
Table 4-28 Barrier Insertion Loss
Eq. 4-48
Barrier
Insertion
Loss
D
ILbarrier = maxf 0 or (Abarrier - 10(GNB — GB) 1og(50))) Eq. 4-49
A barrier
P
D
GNB
GB
= min f 12 or [5.3 log(P) + 6.71}
For non -absorptive transit barriers within 5 ft of the rail = min f 15 or (5.3 log(P) + 9.7)} For absorptive transit barriers within 5 ft of the rail

2.511 For all other barriers, and for protrusion of terrain = minf 15or(20log( tanh(4.46VP)) + 5)} above the line of sight = path length difference, ft (see figure 4-18)*
= closest distance between the receiver and the source, ft = ground factor G computed without barrier (see Table 4-26) = ground factor G computed with barrier (see Table 4-26) * If the source height (exhaust outlet) for diesel-electric locomotives is not available, assume 15 ft.

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Barrier Parameter P
P= A+B-C
B
c
Source
Barrier
Figure 4-I8 Noise Barrier Parameter "P"
Table 4-29 Attenuation due to Buildings
Receiver
Ground
Condition
Equation
Gaps in the row of buildings constitute less
than 35% of the length of the row
Abuildings = min f 10 or [1.5 (R — 1) + 5])
Eq. 4-50
Gaps in the row of buildings constitute 35 to
65% of the length of the row
Abuildings = min f 10 or [1.5 (R - 1) + 3])
Eq. 4-5
Gaps in the row of buildings constitute more
than 65% of the length of the row
Abuildings = 0
R = number of rows of houses that intervene between the source and receiver Table 4-30 Attenuation due to Trees
Condition
Equation
At least 100 ft of trees intervene between the
source and receiver with no clear line -of -sight
between source and receiver, and the trees
extend 15 ft or more above the Tine -of -sight
[io
Atrees = min or where W ≥ l00ft
J
= 0 where W < 100 f t
Eq. 4-52
W = width of tree zone along the line -of -site between the source and receiver in feet Example 4-9: Detailed Noise Analysis — Shielding
Computation of Shielding
The following features are between the rail corridor and a receiver of interest. Calculate the attenuation due to shielding.

1. A 15 -foot high noise barrier is 40 ft from the closest track and 130 ft from the receiver

2. A dense tree zone 100 ft thick that extends 15 ft above the line -of -sight Assumptions
HS =8ft
Hr =5ft
Barrier dimensions
A = 40.61 ft
B = 130.38 ft
C = 170.03 ft
Barrier
Calculate Heff with and without the barrier using the equations in Table 4-26.

Hs + 2Hb + Hr
Heff.NoBarrier = 2
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8+0+5
2 = 6.5 ft
He (.Barrier
HS+2Hb+Hr
2 8+15+5
2 = 21.5 ft
Determine the ground factor with and without the barrier using Eq. 4-43.

GNoearrier = 0.75(1 — Neff)
= 0.63
GBarrier = 0.75(1 - Heff
42 )
= 0.37
Calculate the barrier insertion loss using Table 4-28 and Figure 4-18.

P =A+B-C
= 0.96 ft
A barrier
I Lbarrier

2.51-P
= min{15or(20 log( ) + 5)}
tanh(4.46vP)
= 12.8 dB
= min f 15 or 12.8}
= 12.8 dB
D
= max{0 or (Abarrier - 10(GNoBarrier - GBarrier) log(50))) 170
= 12.8 - 10(0.63 - 0.37) log( 50 )
= 11.4 dB
Trees
Determine the attenuation due to trees using Table 4-30.

W
Atrees = min{10 or 20}
= 5 dB
Total Shielding
The total shielding is the maximum of the barrier and tree zone shielding, I I.4 dB.

Ashielding = max{ILbarrier or Abuildings
= max{11.4 or 0 or 5}
= 11.4 dB
or Atrees}
Note: Computation results should always be rounded to the nearest decibel at the end of the computation. In all examples of this section, however, the first decimal place is retained for readers to precisely match their own computations against the example computations.

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3c. Combine the two propagation characteristics.

Combine the results from Steps 3a and 3b to determine the noise at the receiver considering the propagation characteristics of distance and shielding by applying the distance correction and attenuation due to shielding to the project noise exposure level at 50 ft.

The equations in Table 4-3I combine the equations in Steps 3a and 3b.

Table 4-3I Calculate Lan or Leq(Ihr)
Source
Equation*
Stationary Sources
D D
LDistshield = L — 20 log( —) — 10Glog(D) — Ashielding
50 $0
Eq. 4-53
Fixed -guideway rail car
passbys
D D
LDistshield = L — 101og(5o) — 10Glog(4z) — Ashielding
E . 4-54
q
Fixed -guideway locomotive
and rubber -tired vehicle
passbys, highway vehicle
passbys and horns
D D
LDistshield = L — 101og(5o) — 10Glog(29) —Ashielding
Eq. 4-55
L = Ldn or Lee
D = distance, ft
G = ground factor, see Section 4.5, Step 3a
Ashielding = attenuation due to shielding, see Section 4.5, Step 3b. *These equations assume the distance between the source and receiver is approximately 300 ft or less. At longer distances, ground effects have an upper limit and atmospheric conditions may affect propagation characteristics.

Therefore, more detailed calculation methods may be required to account for those effects.(28, 29) Step 4: Combine Noise Exposure from All Sources
Combine all sources to predict the total project noise at the receivers using the equations in Table 4-32 after propagation adjustments have been made for the noise exposure from each source separately.

Table 4-32 Computing Total Noise Exposure
Total Leq(Ihr) from all sources
for the hour of interest:

LAeq(lhr)/10
Leq.total(lhr) = 10Iog(�all sources 10 )
Eq. 4-56
Total Lar, from all sources
L = 1010 10Ldn/ g(� 10)
dn.total all sources
Eq. 4-57
Example 4-10 Detailed Noise Analysis — Combine Sources
Computation of Total Exposure from Combined Sources
Combine the noise exposure from the commuter train and light rail system to estimate the total noise exposure at the receiver.

Assumptions
A commuter train operation produces the following levels at a receiver of interest:

Leg Commuter = 72 dBA
Ldn.commuter = 68 dBA
A light rail system produces the following levels at the same receiver:

Leq.LtghtRail = 69 dBA
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Ldn.LightRail = 70 dBA
No other project sources affect this receiver.

Calculate the total noise exposure at the receiver using the equations in Table 4-32.

Leq.total
Ldn.total
= 10log(10(72/10) + 10(69/10)
= 73.8 dBA
= 101og(10(68/10) + 10(70/10))
= 72.1 dBA
Note: Computation results should always be rounded to the nearest decibel at the end of the computation. In all examples of this section, however, the first decimal place is retained for readers to precisely match their own computations against the example computations.

Step 5: Determine Existing Noise Exposure
Choose the appropriate method for characterizing noise and then determine the existing noise at each identified noise -sensitive receiver. The existing noise is needed to determine the noise impact according to the criteria described in Section 4.1, Step 2. Recall that impact is assessed based on a comparison of the existing ambient noise exposure and the additional noise exposure that will be caused by the project. The existing noise exposure must be estimated for all receivers of interest identified in Section 4.5, Step I.

For a Detailed Noise Analysis, it is recommended to measure existing noise at each receiver of interest identified in Section 4.5, Step I, for the most precise assessment of existing noise and conclusions concerning noise impact. However, measurements are expensive, often thwarted by weather, and take considerable time in the field. If taking measurements at each identified receiver is not possible, other less precise methods are available. Different methods may be used at different receivers along the project. However, it is important to recognize the correlation between the precision of measurements and the confidence in the impact assessment. Especially in a Detailed Noise Analysis, avoid using less precise methods of measuring existing noise just for the sake of convenience or expediency. The use of less precise methods must be clearly justified.

Option A. Noise Exposure Measurements — Full one -hour measurements are the most appropriate way to determine ambient noise exposure for non-residential receivers with the level of precision expected in a Detailed Noise Analysis. For residential receivers, full 24 -hour measurements are more appropriate. These full -duration measurements are preferred over other methods of characterizing existing noise where time and study funds allow.

Follow the procedures below for these full -duration ambient noise exposure measurements:

Ai. Non-residential land uses — Measure a full hour Leq(Ihr> at the receiver of interest on at least two non -successive weekdays (generally between noon on Monday and noon on Friday). Select the hour of the day when the maximum project activity is expected to occur.

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A.ii. Residential land uses — Measure a full 24 -hour Ldn at the receiver of interest for a single weekday (generally between noon on Monday and noon on Friday).

A.iii. Microphone position — The location of the microphone at the receiver depends upon the proposed location of the transit noise source, so use good technical judgment in positioning the measurement microphone. If, for example, a new rail line will be in front of the house, do not locate the microphone in the backyard behind the house where the line of sight between the noise source and receiver is obstructed. Figure 4-19 illustrates recommended measurement positions for various locations of the project, with respect to the house and the existing source of ambient noise.

A.iv. Measurement guidelines — Undertake all measurements in accordance with good engineering practice following guidelines given in ASTM and ANSI standards.(30)(3I)
I I I I I 1 I l I r M I
I
i
I
I
Project Source i
Ambient Source
- -
•
or • or •
House
Offset: 6 to 10 ft
Ambient Source
Project Source
-
I
•

I I F I
Or • Or •
I I I 1 t 1 I I I
I
I
I
I
House
t
Offset: 6 ft or More
Project Source
Ambient Source
i
i I
I I i
Houma
Offset: to 10 ft
On Centerline
-
u3
m
A
I
Project Source
{
I
.............. Predict Project Noise
Measure Ambient Noise
rouse
•
Offset: 6 to 18 8
On Centerline
• = Microphone Location
Figure 4-I9 Recommended Microphone Locations
for Existing Noise Measurements
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Option B. Noise Exposure Computations from Partial Measurements — Often, measurements can be made at some of the receivers of interest and used to estimate noise exposure at nearby receivers. In other situations, several Leq(Ihr) measurements can be taken at a receiver and then the Ldn computed from these. Both options require experience and knowledge of acoustics to select representative measurement sites. If using this method to compute an Ldn, a minimum time period of one hour should be used for each measurement period. It is unacceptable to extrapolate a one hour measurement from a shorter measurement period.

Measurements at one receiver can be used to represent the noise environment at other sites, but only when proximity to major noise sources is similar among the sites. Residential neighborhoods with otherwise similar homes may have greatly varying noise environments. For example, one area of the neighborhood may be located where the ambient noise is clearly due to highway traffic. A second area toward the interior of the neighborhood may have highway noise as a factor, but also include other noise sources from the community. A third area located deep into the residential area could have local street traffic and other community activities dominate the ambient noise. In this example, three or more measurement sites would be required to represent the varying ambient noise conditions in a single neighborhood.

Typical situations where representative measurement sites can be used to estimate noise levels at other sites occur when both share the following characteristics:
• Proximity to the same major transportation noise sources, such as highways, rail lines and aircraft flight patterns
• Proximity to the same major stationary noise sources, such as power plants, industrial facilities, rail yards and airports
• Similar type and density of housing, such as single-family homes on quarter -acre lots and multi -family housing in apartment complexes Acoustical professionals are often adept at such computations from partial data and are encouraged to use their experience and judgment in fully utilizing the measurements in their computations. This does necessitate a conservative estimate (underestimate) of existing noise to account for reduced precision from partial data as compared to full noise measurements.

Those without a background in acoustics are encouraged to use the procedures in Appendix E to compute existing noise from partial measurements. These methods include a factor to conservatively estimate (underestimate) existing noise to account for reduced precision from partial data as compared to full noise measurements.

Option C. Estimating Existing Noise Exposure — The least precise way to determine noise exposure is to estimate it from a table. This method is often used for the General Noise Assessment, but it is not recommended for a Detailed Noise Analysis. It can be used, however, in the absence of better data for locations where roadways or railroads are the predominant ambient noise source. Table 4-17 presents these existing levels. The levels in Table 4-17 are FEDERAL TRANSIT ADMINISTRATION 94

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conservative and underestimate existing noise to account for reduced precision compared to full noise measurements. If a simplified procedure to estimate existing noise exposure is chosen it must be clearly justified and receive approval by the FTA Regional office.

While measurements are considered the most precise method, there is one situation where it may be more accurate to estimate rather than measure the existing noise exposure, which is in areas near major airports where aircraft noise is dominant. Because airport noise is highly variable based on weather conditions and corresponding runway usage, it is preferable in such cases to base the existing noise exposure on published aircraft noise contours in terms of Annual Average Ld,,.

Step 6: Assess Noise Impact
Assess noise impact at each receiver of interest identified in Section 4.5, Step I using the noise impact criteria in Section 4. I and the procedures in this step.

Choose the appropriate noise impact assessment procedure for a transit project or multimodal project.

Option A. Transit Projects — For transit projects, noise impact is assessed at each receiver of interest using the criteria for transit projects described in Section 4.1. The noise impact assessment procedure is as follows:

A.i. Tabulate existing ambient noise exposure (rounded to the nearest whole decibel) at all receivers identified Section 4.5, Step 1. In cases where large residential buildings are exposed to noise on one side only, the receivers on that side are included in the analysis.

A.ii. Tabulate project noise exposure at these receivers from Section 4.5, Step 4.

A.iii. Determine the level of noise impact (no impact, moderate impact, or severe impact) according to Section 4.1.

A.iv. Document the results in noise -assessment inventory tables. Include the following information:
• Receiver identification and location
• Land use description
• Number of noise -sensitive sites represented (number of dwelling units in residences or acres of outdoor noise -sensitive land) • Closest distance to the project
• Existing noise exposure
• Project noise exposure
• Level of noise impact (no impact, moderate impact, or severe impact) • A sum of the total number of receivers and numbers of dwelling units predicted to experience moderate impact or severe impact A.v. Illustrate the areas of moderate impact and severe impact. Two methods of displaying impact are labeling and contouring.

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■ In a Detailed Noise Analysis, the most accurate indication of impact is to label each impacted building or cluster identified in the inventory table.
■ A less precise illustration of impacted areas is a plot of project noise contours on the maps or aerial photographs, along with shaded impact areas. Use the procedures in Section 4.4, Step 6 and the levels from Section 4.5, Step 2 to develop these contours.

Note that it is difficult to position noise contours in urban areas due to shielding, terrain features, and other propagation anomalies. If noise contours are used, they should be considered illustrative rather than definitive. If desired to conform to the practices of another agency, the contouring may perhaps include several contour lines of constant project noise, such as Ldn 65, Ldn 70, and Ldn 75 dBA.

A.vi. Including information on the magnitude of the impacts is an essential part of the assessment. The magnitude of noise impact is defined by the two threshold curves delineating onset of moderate impact and severe impact.

Option B. Multimodal Projects — For multimodal projects, project noise comprised of both highway and transit noise sources that are assessed according to the FTA noise impact criteria (see Table 4-2), use the procedure in Option A above. For multimodal projects that require FHWA's noise assessment methods to inform FTA's evaluation (see Section 4.1, Step I - Option B), follow the FHWA guidance.(32) In general, the appropriate calculation method is to use the current version of FHWA's Traffic Noise Model (TNM).(22) TNM is a state-of-the-art computer program used for predicting noise impacts near highways.

TNM allows for a detailed assessment at each receiver of interest by separately calculating the noise contribution of each roadway segment. For each roadway segment, the noise from each vehicle type is computed from reference noise levels, adjusted for:
■ Vehicle volume
■ Vehicle speed
■ Grade
■ Roadway segment length
■ Source -to -receiver distance
Further adjustments needed to accurately model the sound propagation from source to receiver include:
■ Shielding provided by rows of buildings,
■ Effects of different ground types,
■ Source and receiver elevations, and
■ Effect of any intervening noise barriers.

TNM sums the noise contributions of each vehicle type for a given roadway segment at the receiver. TNM then repeats this process for all roadway segments, summing their contributions to generate the predicted noise level at each receiver.

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Step 7: Determine Noise Mitigation Measures
Evaluate alternative mitigation measures where the Detailed Noise Analysis shows either severe or moderate impact, and it is not feasible to change the alignment or location of the project to avoid impact. Project noise that is found to cause no impact does not generally require any mitigation.

Mitigation of noise impact from transit projects may involve treatments at the three fundamental components of the noise problem: at the noise source, along the source -to -receiver propagation path, or at the receiver. Generally, the transit property has authority to treat the source and some elements of the propagation path, but may have little or no authority to modify anything at the receiver. After mitigation options have been determined, repeat the project noise computations including the adopted mitigation and reassess the remaining noise impact.

Approximate costs for noise control measures are documented in a report from the Transit Cooperative Research Program (TCRP)(33) and are also presented in this section. These costs reflect the noise mitigation costs available in 1997 (unless otherwise noted), which are the most recent data available as of this publication, and should only be used as representative estimates when considering noise mitigation options. Current noise mitigation costs should be researched before decisions on noise mitigation options are finalized, and then they should be documented according to Section 8.
7a. Evaluate Source Treatments — The most effective noise mitigation treatments are applied at the noise source. This is the preferred approach to mitigation when possible. Common source treatments and their estimated acoustical effectiveness are included in Table 4-33 and described below. It is important to note that the values below are estimates and should be applied with good engineering judgement. It also important to note that these mitigation measures should not be applied as a reduction in the reference SEL values for a vehicle that already incorporates that measure as a feature, such as vehicle skirts. Measurements to determine the reference SEL source level are required in those instances.

Table 4-33 Transit Noise Mitigation Measures — Source Treatments Mitigation Measure
Effectiveness
Stringent Vehicle & Equipment Noise Specifications
Varied
Operational Restrictions--
Varied
Resilient or Damped Wheels*
For rolling noise on tangent track:
2 dB
For wheel squeal on curved track:

I0-20 dB
Vehicle Skirts*
6-10 dB
Undercar Absorption*
5 dB
Quiet Fan Design and Fan Placement*
Varied
Preventative Maintenance on Rail Systems*
Varied
Resurfacing Roads**
I 0 dB
Guideway Support for Buses**
I 0 dB
Turn Radii Greater than 1000 ft*
Avoids Squeal
Rail Lubrication on Sharp Curves*
Reduces Squeal
Movable -Point Frogs (reduce rail gaps at crossovers)*
Reduces Impact Noise
Engine Compartment Treatments
6-I0 dB
Quiet Zones*
Reduces occurrence of horn noise
t FTA does not normally accept operational restrictions as a noise mitigation measure — see below. * Applies to rail projects only.
** Applies to bus projects only.

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■ Stringent Vehicle and Equipment Noise Specifications
• Vehicles — Among the most effective noise mitigation treatments is noise control during the specification and design of the transit vehicle.

Such source treatments apply to all transit modes. By developing and enforcing stringent but achievable noise specifications, the transit property takes a major step in controlling noise everywhere on the system. It is important to ensure that the noise levels quoted in the specifications are achievable with the application of best available technology during the development of the vehicle and reasonable considering the noise reduction benefits and costs.

Effective enforcement includes penalties for non-compliance with the specifications. The noise mitigation achieved by source treatment is dependent on the quality of installation and maintenance. Vehicles failing to meet the noise specification could result in complaints from the public and require additional noise mitigation measures applied along the path or at receivers.
• Stationary sources — Stringent but achievable noise specifications for stationary sources are also an effective approach for mitigating noise impacts. Typical equipment includes fixed plant equipment such as transformers and mechanical equipment, as well as grade -crossing signals. For example, it may be possible to reduce noise impact from grade -crossing signals in some areas by specifying equipment that sets the level of the warning signal lower in locations where ambient noise is lower to minimize the signal noise in the direction of noise -sensitive receivers.
• Operational Restrictions — Changes in operations that can mitigate noise include the lowering of speed, the reduction of nighttime (I0 p.m. to 7 a.m.) operations, and reduction of warning horns and signals. • Speed reduction — Because noise from most transit vehicles is dependent on speed, a reduction of speed results in lower noise levels.

The effect can be considerable. For example, the speed dependency of steel-wheel/steel-rail systems for Leq(Ihr) and Ldn (Table 4-21) results in a 6 -dB reduction when reducing the speed to half of the original speed.

Although there are tangible benefits from speed reductions during the most noise -sensitive time periods, FTA does not ordinarily accept speed reduction as a noise mitigation measure for two important reasons:
speed reduction is unenforceable and negated if vehicle operators do not adhere to established policies, and it is contrary to the purpose of the transit investment by FTA, which is to move as many people as possible as efficiently and safely as possible.
• Reduction of nighttime operations — Complete elimination of nighttime operations has a strong effect on reducing the Ldn, because nighttime noise is increased by I 0 dB when calculating Ldn. But restrictions on operations are usually not feasible because of service demands. FTA generally does not pursue restrictions on operations as a FEDERAL TRANSIT ADMINISTRATION 98

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noise reduction measure. However, if early morning idling can be curtailed to the minimum necessary, however, this can have a measurable effect on Ldn.

While there are tangible benefits from limits on operations during the most noise -sensitive time periods, FTA does not recommend limits on operations as a way to reduce noise impacts because it is contrary to the purpose of the transit investment by FTA which is to move as many people as possible as efficiently and safely as possible.

Reduction of warning horns and signals — Minimizing or eliminating horns and other warning signals at gate crossings can reduce noise impact for light rail and commuter rail systems. Although these mitigation options are limited by safety considerations, they can be effective in the right circumstances. For examples, see quiet zones below and wayside horns in Step 7b.
• Wheel Treatments (Rail) — A major source of noise from steel -wheel and steel -rail systems is the wheel/rail interaction that can produce three distinctive sounds: roar, impact, and squeal (as discussed in Section 3.2).

Roar is the rolling noise caused by small-scale roughness on the wheel tread and rail running surface. Impacts are caused by discontinuities in the running surface of the rail or by a flat spot on the wheels. Squeal occurs when a steel -wheel tread or its flange rubs across the rail, resulting in resonant vibrations in the wheel that creates a screeching sound. Various wheel designs and other mitigation measures exist to reduce the noise from each of these three mechanisms.
▪ Resilient wheels — Resilient wheels are effective in eliminating wheel squeal on tight turns with reductions of I O to 20 dB in the high - frequency range where squeal noise occurs. Rolling noise is also slightly reduced with resilient wheels and typically achieves a 2 -dB reduction on tangent track. The costs for resilient wheels are approximately $2000 to $3000 per wheel, as compared to about $400 to $700 for standard steel wheels.(vi)
▪ Damped wheels — Damped wheels, like resilient wheels, are effective in eliminating wheel squeal on tight turns with reductions of 5 to 15 dB in the high -frequency range where squeal occurs. Rolling noise is also slightly reduced by approximately 2 dB on tangent track. This treatment involves attaching vibration absorbers to standard steel wheels. The costs for damped wheels add approximately $500 to $ 1000 to the normal $700 for each steel wheel.
vl Assumes 8 wheels per vehicle.

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■ Vehicle Treatments — Vehicle noise mitigation measures are applied to the various mechanical systems associated with propulsion, ventilation, and passenger comfort. Propulsion systems of transit vehicles include diesel engines, electric motors, and diesel-electric combinations. Noise from the propulsion system depends on the type of unit and how much noise mitigation is built into the design. Mufflers on diesel engines are generally required to meet noise specifications; however, mufflers are generally practical only on buses, not on locomotives. Control of noise from engine casings may require shielding the engine by body panels without louvers, dictating other means of cooling, and ventilation.

Ventilation requirements for vehicle systems are related to the noise generated by a vehicle. Fan noise often remains a major noise source after other mitigation measures have been instituted because of the need to have direct access to cooling air. This applies to heat exchangers for electric traction motors, diesel engines, and air-conditioning systems. The mitigation options for these systems include:

Quiet fan design and placement — Fan noise can be reduced by installation of quiet, efficient fans. Forced -air cooling on electric traction motors can be quieter than self -cooled motors at operating speeds.

Placement of fans on the vehicle can make a considerable difference in the noise radiated to the wayside or to patrons on the station platforms.
▪ Vehicle skirts and undercar absorption — The vehicle body design can provide shielding and absorption of the noise generated by the vehicle components. Acoustical absorption under the car has been demonstrated to provide up to 5 dB of mitigation for wheel/rail noise and propulsion -system noise on rapid transit trains. Similarly, vehicle skirts over the wheels can provide more than 5 dB of mitigation. By carrying their own noise barriers, vehicles with these features can provide cost-effective noise reduction. The cost for vehicle skirts will add approximately $5000 to $ 10000 per vehicle. Undercar absorption will add approximately $3500 per vehicle, assuming that 50% of the underside of the floor is treated.
• Preventative Maintenance (Rail) — Preventative maintenance is the best strategy to minimize rail and wheel deterioration. While these are not mitigation measures in the traditional sense and should not be included as mitigation in an environmental document, they can help to keep both noise and vibration levels at a "like -new" level or reduce both noise and vibration in systems with deferred maintenance. This can be accompanied by considerable life cost benefits for the transit system. • Spin -slide control systems — Similar to anti -locking brake systems (ABS) on automobiles, spin -slide control systems reduce the incidence of wheel flats, a major contributor of impact noise. Trains with smooth wheel treads can be up to 20 dB quieter than those with wheel flats. To be effective, the anti -locking feature should be in operation during all braking phases, including emergency braking. Wheel flats are more likely FEDERAL TRANSIT ADMINISTRATION 100

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to occur during emergency braking than during dynamic braking. The cost of slip -slide control may be incorporated in the new vehicle costs, but may be between $5,000 and $ 10,000 per vehicle with a maintenance cost of $200 per year.
° Wheel truing — Maintenance of wheels by truing eliminates wheel flats from the treads and restores the wheel profile. As discussed above, wheel flats are a major source of impact noise. As a guideline, it is recommended that wheel sets match within approximately ±0.0 I inch and all wheels on the same truck should match within ±0.02 inches to minimize damage and wear to wheels and rails.(34) A wheel truing machine costs approximately $ I million, including associated maintenance materials and labor costs. The TCRP report estimates a system with 700 vehicles would incur a yearly cost of $300,000 to $400,000 for a wheel truing program.

It is recommended to install wheel -flat detector systems to identify vehicles that are most in need of wheel truing. These systems are becoming more common on railroads and intercity passenger systems, but are relatively rare on transit systems.

Rail grinding — The smoothness of the running surface is critical in the mitigation of noise from a moving vehicle. Mill scale grinding before commencement of pre -revenue service train operations is critical.

Experience shows that grinding new rails after approximately 3 months of train operations and scheduling routine grinding at approximate intervals of 2 years in the problem areas would minimize noise problems related to corrugation in most cases. Grinding with small machines when the corrugation depth is still small is a reasonable approach. As a guideline, it is recommended to spot -grind at locations where corrugation occurs before corrugation grows to 0.02 inches (32).

Periodic rail grinding can result in a net savings per year on wheel and rail wear. Most transit systems contract out rail grinding, although some of the larger systems make the investment of approximately $ I million for the equipment and do their own grinding. Contractors typically charge a fixed amount per day for the equipment on site, plus an amount per pass -mile (one pass of the grinding machine for one mile).

Typical rail grinding cost would be approximately $7,000 to $ 10,000 per pass -mile.

Wheel and rail profile matching — It is important to consider the wheel and rail profile compatibility when truing wheels and grinding rails. If the profiles do not match, the benefits of this kind of preventative maintenance will not be achieved.

It is equally important to consider initial wheel and rail profile compatibility. Work with track designers and vehicle suppliers early in the design process to ensure wheel and rail profile compatibility.

Profiles should be defined during the design phase and should be in FEDERAL TRANSIT ADMINISTRATION 101

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place when system opens.(32) The cost of wheel and rail profile matching may be incorporated in the new vehicle and new rail costs.

Profile grinding of the rail head in combination with a wheel truing program may be the most practical approach to controlling and reducing noise and vibration where such practices are not normally conducted.
▪ Maintenance program — Clearly defined maintenance specifications should be developed during design phase of the project. The specifications should define rail and wheel profiles, include detailed guidance for pre -revenue mill scale grinding, address issues related to healthy rail -wheel interface, and include a mechanism for periodic monitoring of wheel and rail condition and verification for compliance.(32) A diligent maintenance program can often resolve or reduce rail noise issues before they occur. Vehicle reconditioning programs should also be developed particularly for components such as suspension system, brakes, wheels, and slip -slide detectors. ■ Guideway Support (Bus) — The smoothness of the running surface is critical in the mitigation of noise from a moving vehicle. ▪ Resurfacing roads — Roughness on the guideway can be eliminated by resurfacing roads, thereby reducing noise levels by up to I 0 dB. ▪ Bridge expansion joint angles and design — Bridge expansion joints are also a source of noise for rubber -tire vehicles. This source of noise can be reduced by placing expansion joints on an angle or by specifying the serrated type rather than joints with right-angle edges. • Turn Radii and Rail Lubrication — For steel-wheel/steel-rail systems with non-steerable trucks and sharp turns, squeal can typically be eliminated by designing all turn radii to be greater than 1000 ft, or 100 times the truck wheelbase, whichever is less. If this is not possible, squeal can be mitigated by installation of lubricators (though the potential environmental impacts of lubricant application should be factored into this decision).Rail lubricators cost approximately $ 10,000 - $40,000 per curve.
• Movable -point and Spring -rail Frogs — Frogs with spring -loaded mechanisms and frogs with movable points can reduce impact noise near crossovers. According to the TCRP report, a spring frog costs approximately $ 12,000, twice the cost of a standard frog. A movable point frog involves elaborate signal and control circuitry resulting in higher costs of approximately $200,000.
■ Use of Locomotive Horns at -grade Crossings and Quiet Zones — In cases where commuter rail operations share tracks or ROW with freight or intercity passenger trains that are part of the general railroad system, the safety rules of the FRA, including the Train Horn Rule, apply.(35) The Train Horn Rule requires that locomotive horns be sounded at public highway grade crossings, although some exceptions are allowed in carefully defined circumstances. Locomotive horns are often a major contributor in FEDERAL TRANSIT ADMINISTRATION 102

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projections of adverse noise impact, in the community from proposed commuter rail projects. Since noise barriers are not feasible at highway -rail grade crossings, the establishment of quiet zones could be considered.

Quiet zones can be established in which supplemental safety measures (SSMs) are used in place of the locomotive horn to provide an equivalent level of safety at -grade crossings.(vii) By adopting an approved SSM at each public grade crossing, a quiet zone of at least a half -mile long can be established. These measures are in addition to the standard safety devices required at most public grade crossings (e.g., stop signs, reflectorized crossbucks, flashing lights with gates that do not completely block travel over the tracks). Below are four SSMs that have been predetermined by the FRA to fully compensate for the lack of a locomotive horn:
• Temporary closure of a public highway -rail grade crossing — This measure requires closure of the grade crossing for one period each 24 hours, and the closure must occur at the same time each day. ▪ Four -quadrant gate system — This measure involves the installation of at least one gate for each direction of traffic to fully block vehicles from entering the crossing.
• Gates with medians or channelization devices — This measure keeps traffic in the proper travel lanes as it approaches the crossing.

This denies the driver the option of circumventing the gates by traveling in the opposing lane.
• One-way street with gates — This measure consists of one-way streets with gates installed, so that all approaching travel lanes are completely blocked.

In addition to the pre -approved SSMs, the FRA rule also identifies a range of other measures that may be used in establishing a quiet zone. These could include modified SSMs or non -engineering types of measures, such as increased monitoring by law enforcement for grade crossing violations or instituting public education and awareness programs that emphasize the risks associated with grade crossings and applicable requirements. These alternative safety measures (ASMs) require approval by FRA based on a demonstration that public safety would not be compromised by eliminating horn usage.

The lead agency for designating a quiet zone is the local public authority responsible for traffic control and law enforcement on the roads crossing the tracks. To satisfy the FRA regulatory requirements, the public transit agency must work closely with this agency while also coordinating with any freight or passenger railroad operator sharing the ROW. The final environmental document should discuss the main considerations in adopting the quiet zone including: the engineering feasibility, receptiveness of the local public authority, consultation with the railroad, preliminary cost estimates, and evidence of the planning and interagency coordination that has occurred to date. If a quiet zone will be relied on as a mitigation measure, the final environmental document should provide reasonable vii For more information on quiet zones, visit: https://www.fra.dot.gov/Page/P0889 .

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assurance that any remaining issues can and will be resolved. For more information on documentation requirements see Section 8.

The cost of establishing a quiet zone varies considerably, depending on the number of intersections that must be treated and the specific SSMs, ASMs, or combination of measures that are used. The FRA gives a cost estimate of $ 15,000 per crossing for installing two 100 -foot -long, non -traversable medians that prevent motorists from driving around closed gates. A typical installation of a four -quadrant gate system is in the range of $175,000- $300,000 per crossing.(36) Who pays for the installation of modifications can become a major consideration in a decision to pursue a quiet zone designation, especially in cases where noise from preexisting railroad operations is controversial in the community. In many cases where a quiet zone would mitigate a severe impact caused by the proposed transit project, the costs are covered by the project sponsor and FTA in the same proportion as the overall cost -sharing for the project. 7b. Evaluate Path Treatments — When noise mitigation treatments cannot be applied at the noise source or additional mitigation is required after treating the source, the next preferred placement of noise mitigation is along the noise propagation path between the source and receiver. Common path treatments and their estimated acoustical effectiveness are included in Table 4-34 and described below.

Table 4-34 Transit Noise Mitigation Measures — Path Treatments Mitigation Measure
Effectiveness
Noise barriers close to vehicles
6- I 5 dB
Noise barriers at row line
3- 15 dB(37)
Alteration of horizontal & vertical alignments
Varied
Wayside horns
Varied
Acquisition of buffer zones
Varied
Ballast on at -grade guideway*
3 dB
Ballast on aerial guideway*
5 dB
Resilient track support on aerial guideway
Varied
Vegetation and trees
Varied, see Table 4-30
* Applies to rail projects only.
■ Noise Barriers — Noise barriers are effective in mitigating noise when they break the line -of -sight between source and receiver. The mechanism of sound shielding is described in Section 3.3. The necessary height of a barrier depends on the source height and the distance from the source to the barrier, see Table 4-28 and Figure 4-18.

Noise barriers close to vehicles — Barriers located very close to a rapid transit train, for example, may only need to be approximately 3 to 4 ft above the top of rail to be effective. Standard barriers close to vehicles can provide noise reductions of 6 to I 0 dB.

Noise barriers at ROW line — Barriers on the ROW line or for trains on the far track, the height must be increased to provide equivalent effectiveness to barriers located close to the vehicles.

Otherwise, the effectiveness can drop to 3 dB or less, even if the barrier breaks the line -of -sight.

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All barrier effectiveness can be increased by as much as 5 dB by applying sound -absorbing material to the inner surface of the barrier. The length of the barrier wall is also important to its effectiveness. The barrier must be long enough to block noise from a moving train along most of its visible path. This is necessary so that train noise from beyond the ends of the barrier will not severely compromise noise -barrier performance at noise - sensitive locations. The barrier length can be refined in the engineering phase, closely examining the predicted sound level exceedances at specific receivers, site geometries, and the contribution of barrier flanking noise, then adjusting the length as appropriate.

Noise barriers can be made of any outdoor weather -resistant solid material that meets the minimum sound transmission loss required by the project.

Materials that are commonly used for noise barriers include I 6 -gauge steel, I -inch thick plywood, and any reasonable thickness of concrete. Typically, a surface density of 4 pounds per square foot is required. Areas with strong winds may require more stringent structural requirements. It is critical to seal any gaps between barrier panels and between the barrier and the ground or elevated guideway deck for maximum performance.

Costs for noise barriers (based on highway installations) range from $20 to $25 per square foot of installed noise barrier at -grade with additional cost for design and inspection.(38) Installation on aerial structures could be twice the amount of installation at -grade, especially if the structure has to be strengthened to accommodate the added weight and wind load.

As described in Section 3.3, noise barriers, if not designed and sited carefully, can reduce visibility of trains for pedestrians and motorists, which causes safety concerns. It is important to consult with safety experts in choosing and siting a noise barrier.
• Alteration of Horizontal and Vertical Alignments — Transit alignment in a cut as part of grade separation can accomplish the same result as installation of a noise barrier at -grade or on aerial structure. The walls of the cut serve the same function as barrier walls in breaking the line -of -sight between source and receiver.
• Wayside Horns — The sounding of a locomotive horn as the train approaches an at -grade intersection produces a very wide noise footprint in the community. Using wayside horns at these intersections instead of the locomotive horn can substantially reduce the noise footprint without compromising safety at the grade crossing.

A wayside horn does not need to be as loud as a locomotive horn, and the warning sound is focused only on the area where it is needed. These are pole -mounted horns used in conjunction with flashing lights and gates at the intersection, with a separate horn oriented toward each direction of oncoming vehicle traffic. Noise levels in nearby residential and business areas can be reduced substantially with wayside horns, depending on the location with respect to the grade crossing.

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A plan to use wayside horns in place of the locomotive horn at public grade crossings must be coordinated with several public and private entities, notably the local agency having responsibility for traffic control and law enforcement on the road crossings, the state agency responsible for railroad safety, any railroads that share the ROW, and FRA. Public notification must also be given. Preliminary cost information from testing programs indicates a wayside horn system at a railroad/highway grade crossing costs approximately $50,000.
• Buffer Zones — Because noise levels attenuate with distance, one noise mitigation option is to increase the distance between noise sources and the closest noise -sensitive receivers. This can be accomplished by locating alignments away from noise -sensitive sites. Acquisition of land or purchasing easements for noise buffer zones is an option that may be considered if appropriate for the project.
• Ground Absorption — Ballast on Guideways — Propagation of noise over ground is affected by whether the ground surface is absorptive or reflective. Noise from vehicles on the surface is strongly affected by the character of the ground in the immediate vicinity of the vehicle. Roads and streets for buses are hard and reflective, but the ground at the side of a road has a substantial effect on the propagation of noise to greater distance.

Guideways for rail systems can be either reflective or absorptive, depending on whether they are concrete or ballast. Ballast on a guideway can reduce train noise 3 dB at -grade and up to 5 dB on an aerial structure. • Vegetation and Trees — In almost all cases, vegetation and trees are ineffective at providing noise mitigation. Vegetation and Trees can provide some mitigation if at least 100 ft of trees intervene between the source and receiver, if no clear line -of -sight exists between the source and receiver, and if the trees extend 15 ft or more above the line -of -sight as described in Section 4.5, Step 3b. This is generally not a recommended form of mitigation to pursue.
7c. Evaluate Receiver Treatments — Consider treatments to the receivers when noise mitigation treatments cannot be applied at the source or along the propagation path, or if combinations of treatments are required. Common receiver treatments and their estimated acoustical effectiveness are included in Table 4-35 and are described in this section.

Table 4-35 Transit Noise Mitigation Measures — Receiver Treatments Mitigation Measure
Effectiveness
Acquisition of Property Rights for Construction of Noise Barriers 5- I 0 dB
Building Noise Insulation
5-20 dB
■ Noise Barriers — In certain cases, it may be possible to acquire limited property rights for the construction of noise barriers at the receiver. As discussed above, barriers need to break the line -of -sight between the noise source and the receiver to be effective and are most effective when they are FEDERAL TRANSIT ADMINISTRATION 106

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closest to either the source or the receiver. See Section 3.3 for more information on noise barriers.
■ Building Insulation — In cases where noise barriers are not feasible —such as multi -story buildings, buildings very close to the ROW, or grade crossings —the only practical noise mitigation measure may be to provide sound insulation for the buildings. In these cases, the need for mitigation at locations where impact has been identified will depend on the use (outdoor vs. indoor), any existing outdoor to indoor reduction in noise levels, and the feasibility of constructing effective noise barriers for second stories and above.

Depending on the quality of the original building facade, especially windows and doors, sound insulation treatments can improve the noise reductions from transit noise by 5 to 20 dB. To be considered cost-effective, a treatment should provide a minimum reduction of 5 dB in the interior of the building and meet the Ldn 45 dBA interior criterion. For more information, see Section 4.1.

In many cases, especially in locations with high ambient noise levels, the existing sound insulation of a building may already meet the 45 dBA Ldn interior noise criterion. It is recommended that sound insulation testing be conducted to determine if the existing sound insulation is sufficient or what additional measures would be required to meet the interior criterion.

Effective treatments include:
▪ Caulking and sealing gaps in the building facade; and • Installation of new doors and windows that are specially designed to meet acoustical transmission -loss requirements:
— Exterior doors facing the noise source should be replaced with well-gasketed, solid -core wood doors and well-gasketed storm doors.
— Acoustical windows are typically made of multiple layers of glass with air spaces between to provide noise reduction. Acoustical performance ratings are published in terms of Sound Transmission Class (STC) for these windows. It is recommended to use a minimum STC rating of 39 on any window exposed to the noise source.

These treatments are beneficial for heat insulation as well as for sound insulation, but acoustical windows are typically non -operable and central ventilation or air conditioning is needed. Residents' preferences should be considered.

If needed, additional building sound insulation can be provided by sealing vents and ventilation openings and relocating them to a side of the building away from the noise source. In cases where the noise sources is low - frequency noise from diesel locomotives, it may be necessary to increase the mass of the building facade for wood -frame houses by adding a layer of sheathing to the exterior walls.

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Examples of residential sound insulation for rail or highway projects are limited. However, much practical experience with sound insulation of buildings has been gained through grants for noise mitigation to local airport authorities by FAA.

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SECTION Transit Vibration
5 This section presents the basic concepts of transit ground -borne vibration, also referred throughout this manual as simple "vibration," and low -frequency groundborne-noise that sometimes results from vibration. The steps for the screening and assessing of potential vibration impacts of transit projects for FTA NEPA approval are described in the following sections.

The Source -Path -Receiver framework for ground -borne vibration for a rail system illustrated in Figure 5- I is central to all environmental vibration studies.

The train wheels rolling on the rails create vibration energy that is transmitted through the track support system into the transit structure. The vibration of the transit structure excites the adjacent ground, creating vibration waves that propagate through the ground and into nearby buildings creating ground -borne vibration effects that potentially interfere with activities. The vibrating building components may radiate sound, which this manual refers to as ground -borne noise. Airborne noise from transit sources is covered in Sections 2.3-4.5 of this manual. Ground -borne noise refers to the noise generated by ground -borne vibration.

Soil Vibration
Propagation Path
AV Structural Vibration
(((('
Radiated Sound
Figure 5- I Propagation of Ground -Borne Vibration into Buildings This section contains the following:
• Section 5. I The ground -borne vibration and noise metrics used in this manual
• Section 5.2 An overview of transit vibration sources
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• Section 5.3 An overview of transit vibration paths
• Section 5.4 An overview of receiver factors of transit vibration and a discussion of the technical background for ground -borne noise criteria

5.1 Ground -Borne Vibration and Noise Metrics
Vibration is an oscillatory motion that can be described in terms of the displacement, velocity, or acceleration. Because the motion is oscillatory, there is no net movement of the vibration element and the average of any of the motion metrics is zero. Displacement is the most intuitive metric. For a vibrating floor, the displacement is simply the distance that a point on the floor moves away from its static position. The velocity represents the instantaneous speed of the floor movement and acceleration is the rate of change of the speed.

Although displacement is easier to understand than velocity or acceleration, it is rarely used for describing ground -borne vibration. Most transducers used for measuring ground -borne vibration use either velocity or acceleration.

Furthermore, the response of humans, buildings, and equipment to vibration is more accurately described using velocity or acceleration.

This manual uses the metrics outlined in Table 5- I for transit ground -borne vibration and noise measurements, computations, and assessment. These metrics are consistent with common usage in the United States.

Table 5- I Ground -borne Vibration and Noise Metrics
Metric
Abbreviation
Definition
Vibration Decibels
VdB
The vibration velocity level in decibel scale.

Peak Particle Velocity
PPV
The peak signal value of an oscillating vibration velocity waveform.

Usually expressed in inches/second in the United States.

Root Mean Square
rms
The square root of the arithmetic average of the squared amplitude of the signal.

A -weighted Sound Level
dBA
A -weighted sound levels represent the overall noise at a receiver that is adjusted in frequency to approximate typical human hearing sensitivity. This unit is used to characterize ground -borne noise.

The metrics in the table above are illustrated in Figure 5-2. The components in the figure include:
• Raw signal — This curve shows the instantaneous vibration velocity, which fluctuates positively and negatively about the zero point. • Peak particle velocity (PPV) — PPV is the maximum instantaneous positive or negative peak of the vibration signal. PPV is often used in monitoring of construction vibration (such as blasting) since it is related to the stresses that are experienced by buildings and is not used to evaluate human response.
• Root mean square (rms) velocity — Because the net average of a vibration signal is zero, the rms amplitude is used to describe smoothed vibration amplitude. The rms of a signal is the square root of the FEDERAL TRANSIT ADMINISTRATION 110

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average of the squared amplitude of the signal. The average is typically calculated over a one -second period. The rms amplitude is always less than the PPV(viii) and is always positive. The rms amplitude is used to convey the magnitude of the vibration signal felt by the human body, in inches/second.

Figure 5-2 Vibration Signal in Absolute Units
The PPV and rms velocity are described in inches per second in the United States and meters per second internationally (with several different reference values). Although it is not universally accepted, vibration is commonly expressed in decibel notation. The decibel scale compresses the range of numbers required to describe vibration.

The graph in Figure 5-3 shows the rms curve from Figure 5-2 expressed in decibels.

Vibration velocity level in decibels is defined as:
(-1
L„ = 201og
Vref
where:

Lv = velocity level, VdB
= rms velocity amplitude
= I x I Vin/sec in the USA
ref = I x 10"em/sec internationally'
Eq. 5- I
*Because of the variations in the reference quantities, it is important to be clear about what reference quantity is being used when specifying velocity levels. All vibration levels in this manual are referenced to I x I0-6 inches/second.

The ratio of PPV to maximum rms amplitude is defined as the crest factor for the signal. The crest factor is typically greater than 1.41, although a crest factor of 8 or more is not unusual for impulsive signals. For ground -borne vibration from trains, the crest factor is usually 4 to 5.

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Signal in Terms of RMS Velocity Decibels
Velocity Level -- VdB
60 55
50 45
40 Maximum RMS Level
5 6 7 8 9 10
Time
Figure 5-3 Vibration Signal in RMS Velocity Decibels
Ground -borne noise occurs when vibration radiates through a building interior and creates a low -frequency sound, often described as a rumble, as a train passes by. The annoyance potential of ground -borne noise is typically characterized with the A -weighted sound level. Although the A -weighted sound level is typically used to characterize community noise, characterizing low - frequency noise using A -weighting can be challenging because the non -linearity of human hearing causes sounds dominated by low -frequency components to seem louder than broadband sounds (sounds consisting of many frequency components, with no dominant frequencies) that have the same A -weighted level. The result is that ground -borne noise with a level of 40 dBA sounds louder than 40 dBA broadband noise. Because ground -borne noise sounds louder than broadband noise at the same noise level, the limits for ground - borne noise are lower (i.e., stricter) than would be the case for broadband noise.

5.2 Sources of Transit Ground -borne Vibration
and Noise
Ground -borne vibration can be a concern for nearby neighbors of a transit system route or maintenance facility. However, in contrast to airborne noise, ground -borne vibration is not a common environmental problem. It is unusual for vibration from sources such as buses and trucks to be perceptible, even in locations close to major roads. This section discusses common sources of ground -borne vibration and noise.

Most perceptible indoor vibration is caused by sources within buildings such as operation of mechanical equipment, movement of people, or slamming of doors.

Typical outdoor sources of vibration waves that propagate through the ground and create perceptible ground -borne vibration in nearby buildings include construction equipment, steel -wheeled trains, and traffic on rough roads. If the roadway is fairly smooth, the vibration from rubber -tired traffic is rarely perceptible. Building damage due to vibration is also rare for typical transportation projects; but in extreme cases, such as during blasting or pile - driving during construction, vibration could cause damage to buildings.

Figure 5-4 illustrates common vibration sources and the human and structural response to ground -borne vibration ranging from approximately 50 VdB (below FEDERAL TRANSIT ADMINISTRATION 112

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perceptibility) to 100 VdB (the threshold of potential damage). The background vibration velocity level in residential areas is usually 50 VdB or lower,(ix) and the threshold of perception for humans is approximately 65 VdB. A vibration level of 85 VdB in a residence can result in strong annoyance.

Human/Structural Response
Velocity Typical Sources
Level* (50 ft from source)
Threshold for risk of minor cosmetic —�
damage for fragile buildings
Difficulty with tasks such as
reading a computer screen
Residential annoyance, infrequent
events (e.g. commuter rail)
Residential annoyance, frequent —�
events (e.g. rapid transit)
Limit far vibration sensitive
equipment. Approx. threshold for
human perception of vibration
00 90
80 70
84 + Blasting from construction projects
- Bulldozers and other heavy tracked
construction equipment
- Commuter rail, upper range
- Rapid transit, upper range
- Commuter rail, typical
■— Bus or truck aver bump
" Rapid transit, typical
- Bus or truck,typical
- Typical background vibration
RMS Vibration Velocity Level in VdE relative to 10-8 inches/second Figure 5-4 Typical Levels of Ground -Borne Vibration
Rapid transit or light rail systems typically generate vibration levels of 70 VdB or more near their tracks, while buses and trucks rarely create vibration that exceeds 70 VdB unless there are bumps due to frequent potholes in the road.

Heavy locomotives on diesel commuter rail systems create vibration levels approximately 5 to I 0 dB higher than rail transit vehicles.

Vibration from trains is strongly dependent on factors such as how smooth the wheels and rails are, as well as the resonance frequencies of the vehicle suspension system and the track support system. These systems, like all mechanical systems, have resonances that result in increased vibration response at certain frequencies, called natural frequencies. Unusually rough road or track, steel -wheel flats, geologic conditions that promote efficient propagation of vibration, or vehicles with very stiff suspension systems could increase typical Ix Background vibration is typically well below the threshold of human perception and is of concern only when the vibration affects very sensitive manufacturing or research equipment. Electron microscopes and high -resolution lithography equipment are examples of equipment that is highly sensitive to vibration.

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vibration levels by approximately I O VdB. Common factors that contribute to ground -borne vibration and noise at the source are presented in Table 5-2.

These factors are discussed in more detail throughout this Section.

Table 5-2 Factors that Influence Levels of Ground -Borne Vibration and Noise at the Source Category
Factors
Influence
Operations
and
Vehicles
Speed
Higher speeds result in higher vibration levels. Doubling speed results in a vibration level increase of approximately 4 to 6 dB.

Vehicle
Suspension
Stiff suspension in the vertical direction can increase the effective vibration forces. On transit cars, the primary suspension has the largest effect on vibration levels.

Wheel
Condition
and Type
Wheel flats and general wheel roughness are major sources of vibration from steel wheel/steel rail systems. Resilient wheels on rail transit systems can provide some vibration reduction over solid steel wheels, but are usually too stiff to provide substantial reduction. For more information, see Section 6.4, Step 2.

Guideway
Track/Roadway
Surface
Rough track or rough roads are often sources of excessive vibration. Maintaining a smooth surface will reduce vibration levels.

Track Support
System
On rail systems, the track support system is one of the major components in determining the levels of vibration. The highest vibration levels are created by track that is rigidly attached to a concrete trackbed (e.g., track on wood half -ties embedded in the concrete). The vibration levels are much lower when special vibration control track systems such as resilient fasteners, ballast mats, and floating slabs are used.

Transit
Structure
Heavier transit structures typically result in the lower vibration levels. The vibration levels from a lightweight bored tunnel will usually be higher than from a poured concrete box subway.

Transit System
Elevation
A rail system guideway will be either underground (subway), at -grade, or elevated, with substantial differences in the vibration characteristics at each elevation.
• Underground: vibration is typically the most important environmental factor of interest.
■ At -grade: airborne noise is typically the dominant factor, although vibration and noise can be a problem, particularly at interior locations well isolated from exterior noise.
• Elevated: it is rare for vibration to be an issue with elevated railways except when guideway supports are located within 50 ft of buildings.

Brief discussions of ground -borne vibration and noise sources for different modes of transit are provided below.

At -Grade Heavy Rail and Light Rail
Ground -borne vibration and noise from urban heavy rail and LRT is common when there is less than 50 ft between the track and building foundations. Local geology and structural details of the building determine if the source of complaints is due to perceptible vibration or audible ground -borne noise.

Complaints about ground -borne vibration from surface track are more common than ground -borne noise complaints. A substantial percentage of complaints about both ground -borne vibration and noise correlate with proximity of special track work, rough or corrugated track, or wheel flats. Light rail systems tend to generate fewer complaints than heavy rail due to lower operating speeds.

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Commuter and Intercity Passenger Trains
There is the potential for vibration -related issues when new commuter or intercity rail passenger service (including electric multiple units (EMUs) and diesel multiple units (DMUs)) powered by either diesel or electric locomotives is introduced in an urban or suburban area. Commuter and intercity passenger trains have similar characteristics, but commuter trains typically operate on a more frequent schedule. These passenger trains often share track with freight trains, which have different vibration characteristics as discussed below.

Freight Trains
Local and long-distance freight trains are similar in that they both are diesel - powered and have the same types of cars. They differ in their overall length, number and size of locomotives, and number of heavily loaded cars. However, because locomotive suspensions are similar, the maximum vibration levels of local and long-distance freights are similar. Locomotives and rail cars with wheel flats are the sources of the highest vibration levels.

If the transit project does not in any way change the freight service, tracks, etc., then vibration from the freight line would be part of the existing conditions and need to be considered in terms of cumulative impacts (see Section 6.2, Step 3 on how to consider cumulative impacts). If the project results in changes to the freight path, operations, frequency, etc. (e.g., relocating freight tracks within the ROW to make room for the transit tracks) then those potential impacts and mitigation should be evaluated as part of the proposed project. However, note that vibration mitigation is very difficult to implement on tracks where freight trains with heavy axle loads operate.

High -Speed Passenger Trains
Passenger trains travelling at high speeds, 90 to 250 miles per hour, have the potential for creating high levels of ground -borne vibration. Ground -borne vibration should be anticipated as one of the major environmental impacts of any trains travelling at high speeds located in an urban or suburban area.* For projects that are specifically high-speed transportation refer to the FRA "High - Speed Ground Transportation Noise and Vibration Impact Assessment" guidance manual.(39)
AGT Systems
AGT systems include a wide range of transportation vehicles that provide local circulation in downtown areas, airports, and theme parks. Because AGT systems normally operate at low speeds, have lightweight vehicles, run on elevated structures, and rarely operate in vibration -sensitive areas, ground - borne vibration problems are very rare.

Subway and At -grade Track
While ground -borne vibration produced from trains operating subway and at - grade track have very different characteristics, they have comparable overall vibration velocity levels. Complaints about ground -borne vibration are often more common near subways than near at -grade track. This is not because X Amtrak trains (branded Acela at the time of publication) on the Northeast Corridor between Boston and Washington, DC, which attain moderate to high speeds in some sections with improved track, fit into this category.

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subways create higher vibration levels than at -grade systems, rather because subways are usually located in more densely developed areas in closer proximity to building foundations, and the airborne noise is usually a more serious problem for at -grade systems than the ground -borne vibration. Another difference between subway and at -grade track is that the ground -borne vibration from subways tends to be higher frequency than the vibration from at - grade track, which makes the ground -borne noise more noticeable.

Streetcars
Complaints about ground -borne vibration from street cars are uncommon given that streetcars typically operate at very low speeds (less than 25 mph).

Buses
Because the rubber tires and suspension systems of buses provide vibration isolation, it is unusual for buses to cause ground -borne vibration or noise problems. For most issues with bus -related vibration, such as rattling of windows, the cause is almost always airborne noise and directly related to running surface conditions such as potholes, bumps, expansion joints, or other discontinuities in the road surface (usually resolved by smoothing the discontinuities).

Buses operating inside buildings will likely cause vibration concerns for other building inhabitants. An example of this situation is a bus transfer station in the same building as commercial office space. Sudden loading of a building slab by a heavy moving vehicle or by vehicles running over lane divider bumps can cause intrusive building vibration.

5.3 Paths of Transit Ground -Borne Vibration and
Noise
Vibration travels from the source through the transit structure and excites the adjacent ground, creating vibration waves that propagate through soil layers and rock strata to the foundations of nearby buildings. The vibration then propagates from the foundation throughout the remainder of the building structure. The vibration of the building structure and room surfaces can radiate a low -frequency rumble called ground -borne noise (Figure 5-1).

Soil and subsurface conditions are known to have a strong influence on the levels of ground -borne vibration. Among the most important factors are the stiffness and internal damping of the soil and the depth to bedrock. Vibration propagation is more efficient in stiff clay soils. Shallow rock may concentrate the vibration energy close to the surface, resulting in ground -borne vibration problems at large distances from the track. Factors such as soil layers and depth to water table can have substantial effects on the propagation of ground -borne vibration. These factors are summarized in Table 5-3.

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Table 5-3 Factors that Influence Levels of Ground -borne Vibration and Noise along Path Geology Factors
Influence
Soil type
Vibration levels are generally higher in stiff clay -type soil than in loose sandy soil.

Rock layers
Vibration levels are usually high near at -grade track when the depth to bedrock is 30 ft or less. Subways founded in rock will result in lower vibration amplitudes close to the subway. Vibration levels do not attenuate as rapidly in rock as in soil.

Soil layering
Soil layering can have a substantial effect on the vibration levels since each stratum can have considerably different dynamic characteristics.

Depth to water table
The presence of the water table may have a substantial effect on vibration, but a definite relationship has not been established.

5.4 Receiver Factors that Influence Ground -
Borne Vibration and Noise
Ground -borne vibration is a concern almost exclusively inside buildings. Train vibration may be perceptible to people who are outdoors, but it is very rare for outdoor vibration to cause complaints.

The vibration levels inside a building are dependent on the vibration energy that reaches the building foundation, coupling of the building foundation to the soil, and propagation of the vibration through the building. In general, the heavier a building is, the lower the response will be to the incident vibration energy.

Common factors that contribute to ground -borne vibration and noise at the receiver are presented in Table 5-4.

Table 5-4 Factors that Influence Levels of Ground -Borne Vibration and Noise at the Receiver Receiver Building
Factors
Influence
Foundation type
The heavier the building foundation, the greater the coupling loss as the vibration propagates from the ground into the building.

Building
construction
Each building has different characteristics relative to structure -borne vibration, but, in general, the heavier the building, the lower the levels of vibration. The maximum vibration amplitudes of the floors and walls of a building will often occur at the resonance frequencies of the components of the building.

Acoustical
absorption
The more acoustically absorptive materials in the receiver room, the lower the ground -borne noise level. Note that because ground -borne noise usually is a low - frequency phenomenon, it is affected by low -frequency absorption (e.g., below 250 Hz).

5.5 Human Response to Transit Ground -borne
Vibration and Noise
This section contains an overview of human receiver response to ground -borne vibration and noise. It serves as background information for the vibration impact criteria in Section 6.2.

The effects of ground -borne vibration can include perceptible movement of floors in buildings, rattling of windows, shaking of items on shelves or hanging on walls, and low -frequency noise (ground -borne noise). Building damage is not a FEDERAL TRANSIT ADMINISTRATION 1 17

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factor for typical transportation projects, but in extreme cases, such as during blasting or pile -driving during construction, vibration could cause damage to buildings. Although the perceptibility threshold is approximately 65 VdB, human response to vibration is not usually substantial unless the vibration exceeds 70 VdB (Figure 5-4). A vibration level that causes annoyance is well below the damage risk threshold for typical buildings (100 VdB).

Ground -borne vibration is almost never a problem outdoors. Although the motion of the ground may be perceived, without the effects associated with the shaking of a building, the motion does not provoke the same adverse human reaction. Ground -borne noise that accompanies the building vibration is usually perceptible only inside buildings and typically is only an issue at locations with subway or tunnel operations where there is no airborne noise path or for buildings with substantial sound insulation such as a recording studio.

One of the challenges in developing suitable criteria for ground -borne vibration is that there has been relatively little research into human response to vibration and, specifically, human annoyance with building vibration. The American National Standards Institute (ANSI) developed criteria for evaluation of human exposure to vibration in buildings in 1983,(40) and the International Organization for Standardization (ISO) adopted similar criteria in 1989(41) and revised them in 2003.(42) The 2003 version of ISO 2631-2 acknowledges that "human response to vibration in buildings is very complex." It further indicates that the degree of annoyance cannot always be explained by the magnitude of the vibration alone.

In some cases, complaints are associated with measured vibration that is lower than the perception threshold. Other phenomena such as ground -borne noise, rattling, visual effects such as movement of hanging objects, and time of day (e.g., late at night) all play some role in the response of individuals. To understand and evaluate human response, which is often measured by complaints, all of these related effects need to be considered.

Figure 5-5 illustrates the relationship between the vibration velocity level measured in 22 homes and the general response of the occupants to the vibration from measurements performed for several transit systems along with subjective ratings by researchers and residents. These data are published in the "State -of -the -Art Review of Ground -borne Noise and Vibration."(43) The figure also includes a curve representing the percent of people annoyed by vibration from high-speed trains from a Japanese study for comparison.(44) Both the occupants and the people who performed the measurements agreed that floor vibration in the Distinctly Perceptible range is unacceptable for a residence. The data indicates that residential vibration exceeding 75 VdB is unacceptable for a repetitive vibration source such as rapid transit trains that pass every 5 to 15 minutes. The results from the Japanese study confirm the conclusion that at a vibration velocity level of 75 to 80 VdB, many people will find the vibration annoying. A Transportation Research Board (TRB) study of human response to vibration from 2009 also supports this finding and indicates that incidence of complaints fall rapidly with a level decreasing below 72 V d B. (42) (45)
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Response to Residential Building Vibration
4 to 15 Rapid Transit Trains per Hour
Disagreeable
Distinctly
Perceptible
Barely
Perceptible
Imperceptible
o
o
°'o Annoyed
g-6." o 4 4
f fi ▪ esponse to Rapid
ransitTrains
Range of Response to
Rapid Transit Trains
Response to High -
Speed Trains
55 60 65 70 75 BO 85
Vibration Velocity Level -- dB re 1 micro in./sec
100
BO
60 4o a
20 0
90 Figure 5-5 Response to Transit -Induced Residential Vibration Table 5-5 presents the human response to different levels of ground -borne vibration and noise on which the criteria presented in Section 6.2 are based.

The vibration level (VdB) is presented with the corresponding frequency assuming that the vibration spectrum peaks at 30 Hz or 60 Hz.(xi) The ground - borne noise levels (dBA) are estimated for the specified vibration velocity with a peak vibration spectrum of 30 Hz (Low Freq) and 60 Hz (Mid Freq). Note that the human response differs for vibration velocity level based on frequency. For example, the noise caused by vibrating structural components may cause annoyance even though the vibration cannot be felt. Alternatively, a low - frequency vibration can cause annoyance while the ground -borne noise level it generates does not.
xi The A -weighted level of ground -borne noise can be estimated by applying A -weighting to the vibration velocity spectrum and by subtracting an additional 5 dB for a room with average acoustical absorption. Since the A -weighting at 31.5 Hz is -39.4 dB, if the vibration spectrum peaks at 30 Hz, the A -weighted sound level will be approximately 40 dB lower than the velocity level. If the vibration spectrum peaks at 60 Hz, the A -weighted sound level will be approximately 25 dB lower than the velocity level.

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Table 5-5 Human Response to Different Levels of Ground -Borne Vibration and Noise Vibration
Velocity Level
Noise Level
Human Response
Low
Freq*
Mid
Freq**
65 VdB
25 dBA
40 dBA
Approximate threshold of perception for many humans. Low - frequency sound: usually inaudible. Mid -frequency sound: excessive for quiet sleeping areas.
75 VdB
35 dBA
50 dBA
Approximate dividing line between barely perceptible and distinctly perceptible. Many people find transit vibration at this level annoying.

Low -frequency noise: tolerable for sleeping areas. Mid -frequency noise: excessive in most quiet occupied areas.
85 VdB
45 dBA
60 dBA
Vibration tolerable only if there are an infrequent number of events per day. Low -frequency noise: excessive for sleeping areas. Mid - frequency noise: excessive even for infrequent events for some activities.
*Approximate noise level when vibration spectrum peak is near 30 Hz. **Approximate noise level when vibration spectrum peak is near 60 Hz.

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SECTION Vibration Impact Analysis
6 The FTA vibration impact analysis process is a multi -step process used to evaluate a project for potential vibration impacts. If impact is determined, measures necessary to mitigate adverse impacts are to be considered for incorporation into the project.(3)
The FTA vibration impact analysis steps are summarized as follows and are described in the following sections:

6.1 Determine vibration analysis level.

6.2 Determine vibration impact criteria.

Option A: General Vibration Assessment Criteria
Option B: Vibration Impact Criteria for a Detailed Vibration Analysis

6.3 Evaluate Impact: Vibration Screening Procedure
Step 1: Classify project vehicles.

Step 2: Determine project type.

Step 3: Determine screening distance.

Step 4: Identify vibration -sensitive land uses.

6.4 Evaluate Impact: General Vibration Assessment.

Step I : Select base curve for ground surface vibration level.

Step 2: Apply adjustments.

Step 3: Inventory vibration impact.

6.5 Evaluate Impact: Detailed Vibration Analysis
Step I: Characterize Existing Vibration
Step 2: Estimate Vibration Impact
Step 3: Assess Vibration Impacts
Step 4: Determine Vibration Mitigation Measures
A similar process for the noise impact analysis is presented in Section 4. After the noise and vibration analyses have been completed, assess construction noise and vibration according to Section 7 and document findings according to Section 8.

6. I Determine Vibration Analysis Level
There are three levels of analysis to assess the potential ground -borne vibration and noise impacts resulting from a public transportation project. The appropriate level of analysis varies by project based on the type and scale of the project, the stage of project development, and its environmental setting. These three levels are: the Vibration Screening Procedure, the General Vibration Assessment, and the Detailed Vibration Analysis. These levels of vibration analysis mirror the levels of noise analysis discussed in Section 4.2.

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impact, the General Vibration Assessment and Detailed Vibration Analysis procedures are used to determine the extent and severity of impact. In some cases, a General Vibration Assessment may be all that is needed. However, if the proposed project is near noise -sensitive land uses and it appears at the outset that the impact would be substantial, it is prudent to conduct a Detailed Vibration Analysis.

The methods for analyzing transit vibration are consistent with those described in recognized handbooks and international standards.(46)(47) Conduct the vibration screening procedure and then determine the appropriate vibration analysis option:

Vibration Screening Procedure — The Vibration Screening Procedure is a simplified method of identifying the potential for vibration impact from transit projects. The Vibration Screening Procedure is applicable to all types of transit projects and does not require any specific knowledge about the vibration characteristics of the system or the geology of the area. This procedure uses simplified assumptions and considers the type of project and the presence or absence of vibration -sensitive land uses within a screening distance that has been developed to identify most potential vibration impacts. If no vibration -sensitive land uses are present within the defined screening distance, then no further vibration assessment is necessary.

The Vibration Screening Procedure steps are provided in Section 6.3, Step I.

General Vibration Assessment — The General Vibration Assessment is used to examine potential impacts to vibration -sensitive land use areas identified in the screening step more closely. It uses generalized information likely to be available at an early stage in the project development process and during the development of most environmental documents.

Vibration levels at receivers are determined by estimating the overall vibration velocity level and A -weighted ground -borne noise levels as a function of distance from the track and applying adjustments to account for factors such as track support systems, vehicle speed, type of building, and track and wheel conditions.

A General Vibration Assessment is sufficient for the environmental review of many projects, including projects that compare transit modal alternatives or relocate a crossover or turnout. The General Vibration Assessment may also be sufficient if it results in a commitment to mitigation that eliminates the vibration impacts, such as a change in transit mode or alignment. However, if impact is identified through the General Vibration Assessment procedures and not mitigated, a Detailed Vibration Analysis of the selected alternative must be completed. Most vibration mitigation measures can only be specified after a Detailed Vibration Analysis has been done.

The General Vibration Assessment procedure is provided in Section 6.3, Step 2.

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of vibration impact for a proposed project and is often accomplished during the engineering phase of a project when there are sufficient data identifying potential adverse vibration impacts from the project. However, a Detailed Vibration Analysis may be warranted earlier in the environmental review process if there are potentially severe impacts due to the proximity of vibration - sensitive land uses. This type of assessment requires professionals with experience in performing and interpreting vibration propagation tests.

A Detailed Vibration Analysis may not be necessary for all segments of a project. Generalized prediction curves from the General Vibration Assessment procedures may be sufficient for most of the alignment, and the Detailed Vibration Analysis procedure may only need to be applied to particularly sensitive receivers (Section 6.3). Note that a Detailed Vibration Analysis is typically required when designing special track -support systems such as floating slabs or ballast mats. These and other costly vibration mitigation measures can only be specified after a Detailed Vibration Analysis has been done in the engineering phase of the project.

The Detailed Vibration Analysis procedure is presented in Section 6.3, Step 3.

6.2 Determine Vibration Impact Criteria
Use the FTA criteria presented in this section when conducting a General Vibration Assessment or a Detailed Vibration Assessment. Like noise, the sensitivity to vibration varies by land use type, and the criteria represent these sensitivities. These criteria are based on national and international standards, (38)(39)(48) as well as experience on human response to building vibration. See Section 5.5 for additional background information on the development of FTA vibration criteria. The criteria for environmental impact from ground -borne vibration and noise are based on the maximum root - mean -square (rms) vibration velocity levels for repeated events of the same source.

Determine the appropriate criteria based on the level of analysis (Section 6. I ).

The impact criteria for the General Vibration Assessment are presented in Option A, and the impact criteria for the Detailed Vibration Analysis are presented in Option B.

Option A: General Vibration Assessment Criteria
Determine the land use according to Step I and the frequency of events according to Step 2. The impact criteria for the General Vibration Analysis are presented in Step 3.

Step I: Land Use Categories
Determine the appropriate land use category for the receiver of vibration impacts of the project or project segment. Sensitive land use categories for vibration assessment are presented in Table 6- I in order of sensitivity. Consider indoor use of the buildings when determining land use categories for ground -borne vibration and noise, since impact is experienced indoors.

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Table 6-I Land Use Categories for General Vibration Assessment Impact Criteria Land Use
Category
Land Use
Type
Description of Land Use Category
_
Special
Buildings
This category includes special -use facilities that are very sensitive to vibration and noise that are not included in the categories below and require special consideration.

However, if the building will rarely be occupied when the source of the vibration (e.g., the train) is operating, there is no need to evaluate for impact. Examples of these facilities include concert halls, TV and recording studios, and theaters.

High
Sensitivity
This category includes buildings where vibration levels, including those below the threshold of human annoyance, would interfere with operations within the building.

Examples include buildings where vibration -sensitive research and manufacturing* is conducted, hospitals with vibration -sensitive equipment, and universities conducting physical research operations. The building's degree of sensitivity to vibration is dependent on the specific equipment that will be affected by the vibration.

Equipment moderately sensitive to vibration, such as high resolution lithographic equipment, optical microscopes, and electron microscopes with vibration isolation systems are included in this category.** For equipment that is more sensitive, a Detailed Vibration Analysis must be conducted.
2 Residential
This category includes all residential land use and buildings where people normally sleep, such as hotels and hospitals. Transit -generated ground -borne vibration and noise from subways or surface running trains are considered to have a similar effect on receivers.***
3 Institutional
This category includes institutions and offices that have vibration -sensitive equipment and have the potential for activity interference such as schools, churches, doctors' offices. Commercial or industrial locations including office buildings are not included in this category unless there is vibration -sensitive activity or equipment within the building. As with noise, the use of the building determines the vibration sensitivity. * Manufacturing of computer chips is an example of a vibration -sensitive process. ** Standard optical microscopes can be impacted at vibration levels below the threshold of human annoyance. *** Even in noisy urban areas, the bedrooms will often be in quiet buildings with effective noise insulation. However, ground - borne vibration and noise are experienced indoors, and building occupants have practically no means to reduce their exposure. Therefore, occupants in noisy urban areas are just as likely to be exposed to ground -borne vibration and noise as those in quiet suburban areas.
• Ground -borne Vibration — Locations with equipment that is highly - sensitive to vibration should be included in category I or assessed using the Detailed Vibration Analysis procedures (Section 6.3, Step 3) and criteria (Section 6.2, Option B) or specific criteria of the equipment manufacturer.

Most computer installations or telephone switching equipment is not considered sensitive to vibration. Although the owners of this type of equipment often are concerned with the potential for ground -borne vibration interrupting smooth operation of their equipment, it is rare for computer or other electronic equipment to be particularly sensitive to vibration. This type of equipment is typically designed to operate in common building environments where the equipment may experience occasional disturbances and continuous background vibration caused by other equipment.
• Ground -borne Noise — Ground -borne noise is typically only assessed at locations with subway or tunnel operations where there is no airborne noise path, or for buildings with substantial sound insulation such as a recording studio. For typical buildings with at -grade or elevated transit operations, the interior airborne noise levels are often higher than the FEDERAL TRANSIT ADMINISTRATION 124

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ground -borne noise levels. For interior rooms or other special cases, ground -borne noise may need to be assessed.

Step 2: Identify Event Frequency
Determine the appropriate frequency of events for the project or project segment.

Community response to vibration correlates with the frequency of events and, intuitively, more frequent events of low vibration levels may evoke the same response as fewer high vibration level events. This effect is accounted for in the ground -borne vibration and noise impact criteria by characterizing projects by frequency of events. Event frequency definitions are presented in Table 6-2.

Table 6-2 Event Frequency Definitions
Category
Definition
Typical Project Types
Frequent Events
More than 70 events per day
Most rapid transit
Occasional Events
30-70 events per day
Most commuter trunk lines
Infrequent Events
Fewer than 30 events per day
Most commuter rail branch lines
Step 3: Apply Impact Criteria by Land Use and Event
Frequency
Select the appropriate impact criteria for ground -borne vibration and noise based on the previously identified land use categories and frequency of events. It is also important to consider the time of vibration sensitivity. If the building is not typically occupied when the vibration source (e.g., train) is operating, it is not necessary to consider impact.

The criteria in this section are appropriate for assessing human annoyance or interference with vibration -sensitive equipment for common projects. While not typical, existing conditions, freight train operations, and building damage may require consideration.
■ Existing Conditions — The criteria in this section do not consider existing conditions. In most cases, the existing environment does not include a substantial number of perceptible ground -borne vibration or noise events.

However, existing conditions must be evaluated in some cases, such as for projects located in an existing rail corridor. For criteria considering existing conditions, see Step 3b.
■ Freight Train Operations — The criteria are primarily based on experience with passenger train operations. Passenger train operations (rapid transit, commuter rail, and intercity passenger railroad) create vibration events that last approximately I 0 seconds or less while a typical line -haul freight train event lasts approximately two minutes. This manual is oriented to transit projects. However, situations will occur when freight train operations must be evaluated, such as when freight train tracks are relocated for a transit project within a railroad ROW. Guidelines on applying these criteria to freight train operations are presented in Step 3c.

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• Building Damage — It is extremely rare for vibration from train operations to cause substantial or even minor cosmetic building damage.

However, damage to fragile historic buildings located near the ROW may be of concern. Even in these cases, damage is unlikely except when the track is located very close to the structure. Damage thresholds that apply to these structures are discussed in Section 7.2, Step 4 on Construction Vibration Impacts.
3a. Choose the impact criteria by land use category and event frequency. The criteria for ground -borne vibration and noise land use categories I -3 are presented in Table 6-3. The criteria are presented in terms of acceptable indoor ground -borne vibration and noise levels. Impact will occur if these levels are exceeded. Criteria for ground -borne vibration are expressed in terms of rms velocity levels in VdB, and criteria for ground -borne noise are expressed in terms of A -weighted sound pressure levels in dBA.

Table 6-3 Indoor Ground -Borne Vibration (GBV) and Ground -Borne Noise (GBN) Impact Criteria for General Vibration Assessment
Land Use Category
GBV Impact Levels
(VdB re I micro -inch /sec)
GBN Impact Levels
(dBA re 20 micro Pascals)
Frequent
Events
Occasional
Events
Infrequent
Events
Frequent
Events
Occasional
Events
Infrequent
Events
Category I : Buildings where
vibration would interfere with
interior operations.
65 VdB*
65 VdB*
65 VdB*
N/A**
N/A''
N/A**
Category 2: Residences and
buildings where people
normally sleep.
72 VdB
75 VdB
80 VdB
35 dBA
38 dBA
43 dBA
Category 3: Institutional land
uses with primarily daytime
use.
75 VdB
78 VdB
83 VdB
40 dBA
43 dBA
48 dBA
* This criterion limit is based on levels that are acceptable for most moderately sensitive equipment such as optical microscopes. For equipment that is more sensitive, a Detailed Vibration Analysis must be performed. ** Vibration -sensitive equipment is generally not sensitive to ground -borne noise; however, the manufacturer's specifications should be reviewed for acoustic and vibration sensitivity.

The criteria for ground -borne vibration and noise for special land uses are presented in Table 6-4. The criteria are presented in terms of acceptable indoor ground -borne vibration and noise levels. Impact will occur if these levels are exceeded. As for the other land uses, the criteria for ground -borne vibration are expressed in terms of rms velocity levels in VdB, and criteria for ground - borne noise are expressed in terms of sound pressure levels in dBA.

Table 6-4 Indoor Ground -Borne Vibration and Noise Impact Criteria for Special Buildings Type of Building or
Room
Ground -Borne Vibration Impact
Levels (VdB re I micro-inch/sec)
Ground -Borne Noise Impact
Levels (dBA re 20 micro -Pascals)
Frequent
Events
Occasional or
Infrequent Events
Frequent
Events
Occasional or
Infrequent Events
Concert halls
65 VdB
65 VdB
25 dBA
25 dBA
TV studios
65 VdB
65 VdB
25 dBA
25 dBA
Recording studios
65 VdB
65 VdB
25 dBA
25 dBA
Auditoriums
72 VdB
80 VdB
30 dBA
38 dBA
Theaters
72 VdB
80 VdB
35 dBA
43 dBA
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3b. Consider the presence of existing vibration conditions.

When the project will cause vibration more than 5 dB above the existing vibration, the existing source can be ignored, and the standard vibration criteria in Step 3a are appropriate. When the project will cause vibration less than 5 dB above the existing vibration level, use the instructions presented in this section to determine the appropriate impact criteria for the project. For information on characterizing existing vibration conditions, see Section 6.2, Step 3.

Use Table 6-5 and Figure 6- I to determine the appropriate impact criteria.

Sources of existing vibration are typically longer in duration than the events introduced into the environment due to the project. The frequency of use in the rail corridor is also a factor in characterizing the existing conditions. Both factors are considered in the process of determining appropriate impact criteria in Table 6-5 and Figure 6-1.

Examples of projects considering the existing vibration conditions in Table 6-5 and Figure 6-1 include:
■ An automated people mover system planned for a corridor with an existing rapid transit service with 220 trains per day that did not have a significant increase in events from the existing 220 trains per day and that is not 3 dB above the existing vibration level would cause no additional impact.
■ Where a new commuter rail line shares a heavily -used corridor with a rapid transit system, the project vibration exceeds the existing vibration level, there is not a significant increase in the number of events, and the project vibration exceeds the existing vibration level by 3 dB or more, the projected vibration levels must be evaluated using the standard impact criteria to determine impact.
■ If a new transit project will use an existing railroad ROW and the location of existing railroad tracks are shifted, existing vibration can be substantial. The track relocation and reconstruction can result in lower vibration levels that would benefit the receivers and not introduce any adverse impact. However, if the track relocation causes higher vibration levels at vibration -sensitive receivers, then the projected vibration levels must be evaluated using the standard impact criteria to determine impact.

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Table 6-5 Impact Criteria Considering Existing Conditions Category
Number of Operations
(At present — without project)
Criteria
Heavily
Used
More than 12 trains per day
Use the standard vibration criteria in Section 6.2, Step 3a for the following scenarios:
• The existing vibration does not exceed the standard
vibration criteria.
• The existing vibration exceeds the standard vibration criteria and there is a significant increase in events.*
• The existing vibration exceeds the standard vibration criteria, and the project vibration is 3 dB or more above the existing vibration.

The project has no impact if the existing vibration exceeds the standard vibration criteria, the number of events does not increase significantly, and the project vibration does not exceed the existing vibration by 3 dB or more.

Moderately
Used
5 — 12 trains per day
Use the standard vibration criteria in Section 6.2 Step 3a for the following scenarios:
• The existing vibration does not exceed the standard
vibration criteria.
■ The existing vibration exceeds the standard vibration criteria, and the project vibration is not 5 dB or more below the existing vibration.

The project has no impact if the existing vibration exceeds the standard vibration criteria and the project vibration is at least 5 dB below the existing vibration.

Infrequently
Used
Fewer than 5 trains per day
The standard vibration criteria in Section 6.2, Step 3a apply. * Approximately doubling the number of events is required for a significant increase.

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Project vita_'
5 dB above
existing?
Infrequently
used corridor
c5 Irains/day
Existing vibration
exceed criteria?
Yes
Projectvib.
5 dB below
existing?
Yes
No impact N
Standard
vibration
assessment
Figure 6-I Existing Vibration"" Criteria Flow Chart
Moderately
used corridor
5-12 Irainsfday
o
Yes
Yes
Heavily used
corridor
>12 trains/day
Existing vibration
exceed criteria?
Yes
Significant
increase in # of
events?
No
No
3c. Apply criteria to freight trains if part of the project.

Use the criteria presented in Step 3a to assess the vibration from freight trains in shared ROW scenarios because no specific impact criteria exist for freight railroads. It is important to consider that freight operations occur over substantially greater distances than passenger train operations and have different weight and axle loads.

When assessing vibration from freight train operations, consider the locomotive and rail car vibration separately. Since locomotive vibration lasts for a very short time, it can be characterized by the infrequent events category in Table 6-2. Rail car vibration from a typical line -haul freight train usually lasts for several minutes and can be characterized by the frequent events category in Table 6-2. Note xii Vibration is abbreviated as "vib." in this flowchart.

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that locomotives often create vibration levels that are 3 to 8 dB higher than those created by rail cars.

Use good engineering judgment to confirm the approach is reasonable for each project. For example, some spur rail lines carry very little rail traffic (sometimes only one train per week) or have short trains, in which case it may not be necessary to evaluate for impact. If there is uncertainty in how to determine the appropriate criteria, contact the FTA Regional office.

Decisions to relocate freight tracks closer to vibration -sensitive sites should be made with the understanding that increased vibration due to freight rail may not be possible to mitigate. Freight rail vibration may not always be successfully mitigated by the same methods as rail transit systems.

Option B: Vibration Impact Criteria for a Detailed Vibration Analysis
Determine the appropriate impact criteria for ground -borne vibration and ground -borne noise for a Detailed Vibration Analysis.

Step I: Ground -Borne Vibration
Choose the appropriate criteria based on Figure 6-2 and Table 6-6.

Ground -borne vibration criteria presented in this section are more detailed than in the General Vibration Assessment. The criteria are based on international standards for the effects of vibration on people related to annoyance and interference with activities in buildings(39) as well as industry standards for vibration -sensitive equipment.(46) The criteria in this section are used to assess the potential for interference or annoyance from building response and to determine performance of vibration reduction methods. Note that for highly -sensitive equipment, specific vibration criteria provided by the manufacturer supersede the criteria in this section.

The criteria are presented by category in Figure 6-2 and are defined by international and industry standards.(39)(46) These criteria define limits for acceptable maximum rms vibration velocity level with a one -second averaging time at the floor of the receiving building in terms of a one-third octave band frequency spectrum. Band levels that exceed a particular criterion curve indicate impact; and therefore, mitigation options should be evaluated considering the specific frequency range in which the treatment is most effective. Interpretations of the criteria are presented in Table 6-6.

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100
90 80
v
J
5 70
Te
a
60 50
40 Workshop
Office
Residential (Day)
Residential (Night)
VC -A
VC -B
VC -C
VC -D
VC -E
4 5 6.3 8 10 12.5 16 20 25 31.5 40 50 63 80
One -Third Octave Band Center Frequency, Hz
Figure 6-2 Criteria for Detailed Vibration Analysis
Table 6-6 Interpretation of Vibration Criteria for Detailed Vibration Analysis Criterion
Curve
Max Lv,*
VdB
Description of Use
Workshop (ISO)
90 Vibration that is distinctly felt. Appropriate for workshops and similar areas not as sensitive to vibration.

Office (ISO)
84 Vibration that can be felt. Appropriate for offices and similar areas not as sensitive to vibration.

Residential Day
(ISO)
78 Vibration that is barely felt. Adequate for computer equipment and low - power optical microscopes (up to 20X).

Residential Night,
Operating Rooms
(ISO)
72 Vibration is not felt, but ground -borne noise may be audible inside quiet rooms. Suitable for medium -power optical microscopes (I 00X) and other equipment of low sensitivity.

VC -A
66 Adequate for medium- to high -power optical microscopes (400X), microbalances, optical balances, and similar specialized equipment.

VC -B
60 Adequate for high -power optical microscopes (I 000X) and inspection and lithography equipment to 3 -micron line widths.

VC -C
54 Appropriate for most lithography and inspection equipment to I -micron detail size.

VC -D
48 Suitable in most instances for the most demanding equipment, including electron microscopes operating to the limits of their capabilities.

VC -E
42 The most demanding criterion for extremely vibration -sensitive equipment.

As measured in I/3 -octave bands of frequency over the frequency range 8 to 80 Hz.

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In addition to the uses described in Table 6-6, the detailed vibration criteria can be applied to the three land use categories presented in Table 6-3. ■ For residential land uses (category 2), use the residential night criterion curve in Table 6-6.
■ For institutional uses (category 3), use the residential day criterion curve in Table 6-6.
■ For category I, the specific use of the building should be matched to the appropriate criterion curve in Table 6-6.
■ For special buildings, such as those found in Table 6-4, either the criteria in Table 6-4 or specific criteria presented by the building operator should be used.

These criteria use a frequency spectrum because vibration -related problems generally occur due to resonances of the structural components of a building or vibration -sensitive equipment. Resonant response is frequency -dependent. A Detailed Vibration Analysis can provide an assessment that identifies potential problems resulting from resonances.

The detailed vibration criteria are based on generic cases when people are standing or equipment is mounted on the floor in a conventional manner.

Consequently, the criteria are less stringent at very low frequencies below 8 Hz.

Where special vibration isolation has been provided in the form of pneumatic isolators, the resonant frequency of the isolation system is very low.

Consequently, in this special case, the curves may be extended flat at lower frequencies.

Step 2: Ground -borne Noise
Ground -borne noise impacts are assessed based on criteria for human annoyance and activity interference. The Detailed Vibration Analysis procedure provides vibration spectra inside a building. To evaluate ground -borne noise, convert these vibration spectra to sound pressure level spectra in the occupied spaces using the method described in Section 6.5 and compare to the criteria as follows:
■ For residential buildings, use the criteria presented in Table 6-3. ■ For special buildings listed in Table 6-4, A -weighted noise may not be sufficient to assess activity interference for a Detailed Vibration Analysis.

Each special building may have a unique specification for acceptable noise levels and criteria must be determined on a case -by -case basis.

For example, a recording studio may have stringent requirements for allowable noise in each frequency band.

6.3 Evaluate Impact: Vibration Screening
Procedure
Determine the potential for impact using the Vibration Screening Procedure by identifying any vibration -sensitive land uses (Table 6-I) within the appropriate screening distance.

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no
yes
No Vibration
Impact Likely
No Further
Analysis Required
Start
Steel -Wheel
Steel -Rail
Project?
no
Vib.

Sensitive
Manufacturing or
Research
no
Vehicles
Operating in
Building?
no
yes
yes
no
Determine Screening
Distances Based on
Project Type and
Land use Categories
Sensitive
Land Uses within
Impact Distances?
yes
Vibration Analysis
Required
Figure 6-3 Flow Chart of Vibration Screening Process
Step I: Classify Project Vehicles
Determine the project type and the next step based on the guidelines below.

Option A: No Vehicles — Transit projects that do not involve vehicles do not have potential for vibration impact and do not require further analysis (Box A in Figure 6-3).

Many smaller FTA-funded projects, such as bus terminals, park -and -ride lots, and station rehabilitation are in this category, and do not require further analysis of ground -borne vibration impact. However, if track systems are modified (e.g., tracks moved or switches modified), proceed to Step 2.

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Option B: Steel-wheeled/Steel-rail Vehicles — Transit projects with steel- wheeled/steel-rail vehicles have potential for vibration impact (Box B in Figure 6-3); proceed to Step 2. These rail systems include urban rapid transit, LRT, commuter rail, and steel -wheel intermediate capacity transit (ICT) systems.

Option C: Rubber -tire Vehicles — For projects that involve rubber -tire vehicles and do not meet the following conditions, vibration impact is unlikely, and no further analysis is needed. Proceed to Step 2 for projects that involve rubber -tire vehicles and meet the following conditions (Box A in Figure 6.3):
■ Roadway irregularity — Expansion joints, speed bumps, or other design features that result in unevenness in the road surface can result in perceptible ground -borne vibration at distances up to 75 ft away. ■ Operation close to vibration -sensitive buildings — Buses, trucks, or other heavy vehicles operating close to a vibration -sensitive building (within approximately 100 ft from the property line) may impact vibration -sensitive activities, such as research that uses electron microscopes or manufacturing of computer chips.
■ Vehicles operating within buildings — Special considerations are often required for shared use facilities where vehicles operate inside or directly underneath buildings such bus stations located inside an office building complex.

Step 2: Determine Project Type
Determine the project type according to Table 6-7.

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Table 6-7 Project Types for Vibration Screening Procedure Project Type
Number
Project
Type
Description
I
Conventional
Commuter
Railroad
Both locomotives and passenger vehicles create vibration. For commuter trains, the highest vibration levels are typically created by the locomotives.

Electric commuter rail vehicles create levels of ground -borne vibration that are comparable to electric rapid transit vehicles.
2 RRT
Ground -borne vibration impact from rapid transit trains is one of the major environmental issues for new systems. Ground -borne vibration is usually a major concern for subway operations. It is less common for at -grade and elevated rapid transit lines to create intrusive ground -borne vibration and noise since air -borne noise typically dominates.
3 LRT and
Streetcars
The ground -borne vibration characteristics of light rail systems are very similar to those of rapid transit systems. Because the speeds of light rail systems are usually lower, typical vibration levels are usually lower. Steel-wheel/steel-rail AGT is included in either this category or the ICT category depending on the level of service and train speeds.
4 Intermediate
Capacity
Transit
Because of the low operating speeds of most ICT systems, vibration problems are not common. However, steel -wheel ICT systems that operate close to* vibration -sensitive buildings have the potential of causing intrusive vibration.

With a stiff suspension system, an ICT system could create intrusive vibration. 5 Bus and
Rubber -Tire
Transit
Projects
This category encompasses most projects that do not include steel -wheel trains of some type. Examples include diesel buses, electric trolley buses, and rubber -tired people movers. Most projects that do not include steel -wheel trains do not cause vibration impacts.**
*See the screening distances for category I land uses in Table 6-8. ** Most complaints about vibration caused by buses and trucks are related to rattling of windows or items hung on the walls.

These vibrations are usually the result of airborne noise and not ground -borne vibration. In the case where ground -borne vibration is the source of the complaint, the vibration can usually be attributed to irregularities in the road.

Step 3: Determine Screening Distance
Determine the appropriate screening distances based on land use and project type according to Table 6-8.

The distances are based on the criteria presented in Section 6.3, the procedures in Section 6.4 assuming normal vibration propagation, and include a 5 -dB factor of safety. Even so, areas with very efficient vibration propagation can have substantially higher vibration levels.

Because of the 5 -decibel safety factor, the screening distances will identify most of the potentially impacted areas, even for areas with efficient propagation.

However, when there is evidence of efficient propagation, such as previous complaints about existing transit facilities or a history of problems with construction vibration, increase the distances in Table 6-8 by a factor of 1.5.

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Table 6-8 Screening Distances for Vibration Assessments Type of Project
Critical Distance for Land Use Categories*
Distance from ROW or Property Line, ft
Land Use
Cat. I
Land Use
Cat. 2
Land Use
Cat. 3
Conventional Commuter Railroad
600
200
120
RRT
600
200
120
LRT and Streetcars
450
150
100
ICT
200
I00
50 Bus Projects (if not previously screened out)
100
50 --
*For the Vibration Screening Procedure, evaluate special buildings as follows: Category I - concert halls and TV studios, Category 2 - theaters and auditoriums
Step 4: Identify Vibration -Sensitive Land Uses
Identify all vibration -sensitive land uses (Table 6- I) within the chosen screening distance. If no vibration -sensitive land uses are identified, no further vibration analysis is needed. If one or more of the vibration -sensitive land uses are in the screening distance, complete a General Vibration Assessment (Section 6.4) or a Detailed Vibration Analysis (Section 6.5).

6.4 Evaluate Impact: General Vibration
Assessment
Evaluate for impact using the General Vibration Assessment procedure if the Vibration Screening Procedure (Section 6.3) identified vibration -sensitive receivers within the screening distance of the transit vibration source.

For guidelines on when the General Vibration Assessment is appropriate, review Section 6. I .

The basic approach for the General Vibration Assessment is to define a curve or set of curves that predicts the overall ground -borne vibration as a function of distance from the source, then apply adjustments to these curves to account for factors such as vehicle speed, geologic conditions, building type, and receiver location within the building. When the vehicle type is not covered by the curves included in this section, it will be necessary to define an appropriate curve either by extrapolating from existing information or performing measurements at an existing facility.

Step I: Select Base Curve for Ground Surface Vibration
Level
Select a standard vibration curve to represent general vibration characteristics for the source.

The curves presented in Figure 6-4 are based on measurements of ground - borne vibration at representative North American transit systems and can be used to represent vibration characteristics for standard transportation systems in the General Vibration Assessment.

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These curves assume typical ground -borne vibration levels, equipment in good condition, and speeds of 50 mph for the rail systems and 30 mph for buses.

Adjustments to account for differences in speed and geologic conditions are included in Step 2.

Select a base curve from Figure 6-4 according to the guidelines in Table 6-9.

Equations for the curves in Figure 6-4 are included in Table 6-10. Additional considerations for selecting a base curve for systems not included in Table 6-9 are presented below by transit mode.

Table 6-9 Ground Surface Vibration Level Base Curve Descriptions Curve
Description
Locomotive -Powered
Passenger or Freight Curve
Appropriate for vehicles powered by diesel or electric locomotives including intercity passenger trains and commuter rail trains.

Rapid Transit or Light Rail
Vehicles Curve
Appropriate for both heavy and light -rail vehicles on at -grade and subway track.

Rubber -Tired Vehicles Curve
Appropriate for rubber -tire vehicles. These types of vehicles rarely create ground -borne vibration problems unless there is a discontinuity or bump in the road that causes the vibration. This curve represents the vibration level for a typical bus operating on smooth roadway.

RMS Velocity level, VdB re 1 micro in./sec
100
95 90
85 80
75 70
65 60
55 50
Locomotive Powered
Passenger or Freight
(50 mph)
Rubber -Tired
Vehicles
(30 mph)
Rapid Transit or
Light Rail Vehicles _
(50 mph)
150 200
10 20 30 40 50 60 80 100
Distance from track centerline, ft
(Use diagonal distance for underground systems)
Figure 6-4 Generalized Ground Surface Vibration Curves
300
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Table 6-IO Generalized Ground Surface Vibration Equations Curve
Equation
Locomotive Powered
Passenger or Freight Curve
L„ = 92.28 + 14.83 log(D) — 14.17log(D)2
+1.65 log(D)3
Eq. 6-I
Transit or Light Rail
Vehicles Curve
L„ = 85.88 — 1.06 log(D) — 2.32 log(D)2
—0.87 log(D)3
Eq. 6-2
Rubber Tired Vehicles Curve
L„ = 66.08 + 34.28 log(D) — 30.25 log(D)2
+5.40 log(D)3
Eq. 6-3
L„ = velocity level, VdB
D = distance, ft
Considerations for selecting a base curve for different transit modes include:
• Intercity passenger trains — Although intercity passenger trains can be an important source of environmental vibration, it is rare that they are considered for FTA-funded projects unless a new transit mode uses an existing rail alignment. When a new transit line uses an existing rail alignment, changes in the intercity passenger traffic can result in either positive or negative impacts. Use the locomotive -powered passenger or freight curve for intercity passenger trains unless there are specific data available on the ground -borne vibration created by the new train operations.
• Locomotive -powered commuter rail — Use the locomotive - powered passenger or freight curve for all commuter rail system powered by either diesel or electric locomotives.
• Electric multiple unit (EMU) — Use the rapid transit or light rail vehicles curve for self -powered electric commuter rail trains. • Diesel multiple unit (DMU) — Self -powered DMUs create vibration levels somewhere between rapid transit vehicles and locomotive - powered passenger trains. A vibration curve for DMUs can be estimated by lowering the locomotive -powered passenger or freight curve by 5 dB.
• Subway heavy rail or light rail — Use the rapid transit or light rail vehicles curve for subway heavy rail and subway light rail. Although vibrations from subway and at -grade tracks have very different characteristics, the overall vibration velocity levels are comparable.

When applied to subways, the rapid transit or light rail vehicles curve assumes a relatively lightweight bored concrete tunnel in soil. The vibration levels will be lower for heavier subway structures such as cut - and -cover box structures and stations.
• At -grade heavy rail or light rail — Use the rapid transit or light rail vehicles curve for at -grade heavy rail or light rail. Heavy rail and LRT vehicles have similar suspension systems and axle loads and create similar levels of ground -borne vibration.

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• Elevated guideways or aerial structures — Vibration from operations on an elevated structure is typically not an issue unless the guideway is supported by a building or located very close to buildings.

Apply the appropriate adjustment for the aerial structures (Section 6.4, Step 2).
■ Streetcars — Use the rapid transit or light rail vehicles curve for street cars.
• ICT — Use the rapid transit or light rail vehicles curve for ICT systems with steel wheels and the rubber -tired vehicles curve for ICT systems with rubber tires.
• Other vehicle types — For less common modes such as magnetically - levitated vehicles (maglev), monorail, or AGT, use good engineering judgment to choose a standard curve to best fit the mode or if a new curve needs to be developed, as a function of distance from the track.

Examples include:
▪ Vibration from a rubber -tire monorail operating on aerial guideway can be approximated using the rubber -tired vehicles curve with the appropriate adjustment for the aerial structure (Section 6.4, Step 2).
▪ Most of the data available on the noise and vibration characteristics of maglev vehicles comes from high-speed systems intended for inter -city service. Even though there is no direct contact between the vehicle and the guideway, the dynamic loads on the guideway can generate ground -borne vibration. Measurements on a German high-speed maglev
resulted in ground -borne vibrations at 75 mph which is comparable to the base curve for rubber -tired vehicles at 30 mph.(49)
Step 2: Apply Adjustments
Apply project -specific adjustments to the standard vibration curve.

Once the base curve has been selected, use the adjustments in the following instructions to develop project -specific vibration projections at each receiver.

All adjustments are given as single numbers to add to, or subtract from, the base level.

Adjustments are separated by source, path, and receiver and include speed, wheel and rail type and condition, type of track support system, type of building foundation, and number of floors above the basement level. Calculate the appropriate adjustments to the base level. An example of the General Vibration Assessment is provided at the end of this Section.

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mitigation measures because they are based on typical vibration spectra.

However, these adjustments are not adequate for detailed evaluations of impact of vibration -sensitive buildings or for detailed specification of mitigation measures.
2a. Apply source adjustments to the base curve using Table 6- I I and the descriptions below to account for the project -specific source characteristics.

Table 6- I I Source Adjustment Factors for Generalized Predictions of GB Vibration and Noise Source
Factor
Adjustment to
Propagation Curve
Comment
Speed
Vehicle
Reference
50 mph
Speed
30 mph
Vibration level is approximately proportional to
201og(speed/speed,ef), see Eq. 6-4.

Speed
+ I.6 dB

0.0 dB

1.9 dB
-4.4 dB
-8.0 dB
+6.0 dB
+4.4 dB
+2.5 dB

0.0 dB
-3.5 dB
60 mph
50 mph
40 mph
30 mph
20 mph
Vehicle Parameters (not additive, apply greatest value only) Vehicle with
stiff primary
suspension
+8 dB
Transit vehicles with stiff primary suspensions have been shown to create high vibration levels. Include this
adjustment when the primary suspension has a vertical
resonance frec uency greater than 15 Hz.

Resilient
Wheels
0 dB
Resilient wheels do not generally affect ground -borne
vibration except at frequencies greater than about 80
Hz.

Worn Wheels
or Wheels with
Flats
+10 dB
Wheel flats or wheels that are unevenly worn can cause
high vibration levels.

Track Conditions (not additive, apply greatest value only) Worn or
Corrugated
Track
+10 dB
Corrugated track is a common problem. Mill scale* on
new rail can cause higher vibration levels until the rail has been in use for some time. If there are adjustments for vehicle parameters and the track is worn or
corrugated, only include one adjustment.

Special
Trackwor
within within 200 ft
+10 dB (within 100 ft)
+5 dB (between 100 and 200 ft)
Wheel impacts at special trackwork will greatly increase vibration levels. The increase will be less at greater
distances from the track. Do not include an adjustment
for special trackwork more than 200 ft away.

Jointed Track
+5 dB
Jointed track can cause higher vibration levels than
welded track.

Uneven Road
Surfaces
+5 dB
Rough roads or expansion joints are sources of
increased vibration for rubber -tire transit.

Track Treatments (not additive, apply greatest value only) Floating Slab
rFl ackbed
T the
-15 dB
The reduction achieved with a floating slab trackbed is strongly dependent on the frequency characteristics of
vibration.

Ballast Mats
I0 dB
Actual reduction is strongly dependent on frequency of
vibration.

High -Resilience
Fasteners
-5 dB
Slab track with track fasteners that are very compliant in the vertical direction can reduce vibration at frequencies greater than 40 Hz.
*Mill scale on a new rail is a slightly corrugated condition caused by certain steel mill techniques.

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In addition to the comments in Table 6-11, use the following guidelines to select the appropriate adjustment factors. Some adjustments in the same category are not cumulative (additive) and only the greatest applicable adjustment should be applied. The adjustments that are not additive are noted in Table 6- I I and in the descriptions below. Note that some adjustments are not additive across multiple categories and are noted in the comments of Table 6- I I . For example, the adjustment for a vehicle with stiff primary suspension is 8 dB, and the adjustment for wheel flats is I 0 dB. If the vehicle has a stiff primary suspension and has wheel flats, the projected vibration levels should be increased by 10 dB, not 18 dB.

In addition, some vibration control measures are targeted for specific frequency ranges. The shape of the actual vibration spectra should be considered so that an appropriate vibration control measure may be selected. • Speed — The levels of ground -borne vibration and noise vary, approximately, as 20 times the logarithm of speed. This means that doubling train speed will increase the vibration levels approximately 6 dB, and halving train speed will reduce the levels by 6 dB. The adjustments in Table 6- I I have been tabulated for reference vehicle speeds of 30 mph for rubber -tired vehicles and 50 mph for steel -wheel vehicles. Use the following relationship to calculate the adjustments for other speeds.
speed
Adjspeed (dB) = 20log(s eed )
p ref
Eq. 6-4
Variation with speed has been observed to be as low
as 15log( speed
speedref but unless specific speed data for vibration for a vehicle has been obtained, use Eq. 6-4.
• Vehicle Parameters — The most important factors for the vehicles are the suspension system, wheel condition, and wheel type. Most new heavy rail and light rail vehicles have relatively soft primary suspensions.

However, a stiff primary suspension (vertical resonance frequency greater than 15 Hz) can result in higher levels of ground -borne vibration than soft primary suspensions. Vehicles, for which the primary suspension consists of rubber or neoprene around the axle bearing, usually have a very stiff primary suspension with a vertical resonance frequency greater than 40 Hz or more.

Deteriorated wheel condition is another factor that increases vibration levels. It can be assumed that a new system has vehicles with wheels in good condition. When older vehicles are used on new track, it is important to consider the condition of the wheels, and it may be appropriate to include an adjustment for the wheel condition.

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frequency is relatively high, greater than 80 Hz, resilient wheels may only have a marginal effect on ground -borne vibration.

The adjustments in this category are not additive; apply the greatest applicable value only.
• Track Conditions — This category includes the type of rail (welded, jointed, or special trackwork), the track support system, and the condition of the rail. The base curves assume welded rail in good condition. Jointed rail causes higher vibration levels than welded rail and the increase depends on the condition of the joints.

Wheel impacts at special trackwork, such as frogs at crossovers, create much higher vibration forces than typical track conditions. Because of the higher vibration levels at special trackwork, crossovers are the principal areas of vibration impact on new systems. Methods of mitigating the vibration impact include modifying the track support system, installing low -impact frogs, or relocating the crossover. Special track support systems such as ballast mats, high -resilience track fasteners, resiliently supported ties, and floating slabs have all been shown to be effective in reducing vibration levels.

The condition of the running surface of the rails can strongly affect vibration levels. Factors such as corrugations, general wear, or mill scale on new track can cause vibration levels 5 to 15 dB higher than normal.

Mill scale will typically wear away after some time in service, but the track must be ground to remove corrugations or to reduce the roughness from wear.

Roadway surfaces in the rubber -tired vehicle base curve are assumed to be smooth. Rough washboard surfaces, bumps, or uneven expansion joints are the types of running surface defects that cause increased vibration levels over the smooth road condition.

The adjustments in this category are not additive; apply the greatest applicable value only. If there are adjustments for vehicle parameters and the track is worn or corrugated, only include one adjustment. 2b. Apply path adjustments to the base curve using Table 6-12 and the descriptions below to account for the project -specific path characteristics.

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Table 6-I2 Path Adjustment Factors for Generalized Predictions of GB Vibration and Noise Path Factor
Adjustment to Propagation Curve
Comment
Resiliently
Supported
Ties
(Low - -10
Vibration
Track, LVT)
dB
Resiliently supported tie systems have been
found to provide very effective control of
low -frequency vibration.

Track Structure (not additive, apply greatest value only) Type of
Transit
Structure
Relative to at -grade tie & ballast:

Elevated structure
Open cut
-I0 dB
0 dB
In general, the heavier the structure, the
lower the vibration levels. Putting the track
in cut may reduce the vibration levels slightly.

Rock -based subways generate higher -
frequency vibration.

Relative to bored subway tunnel
Station
Cut and cover
Rock -based
in soil:
-5 dB
-3 dB
-I5 dB
Ground -borne Propagation Effects
Geologic
conditions that
promote
efficient
vibration
propagation
Efficient propagation in soil
+10 dB
Refer to the text for guidance on identifying
areas where efficient propagation is possible.

Propagation
in rock layer
Dist.

Adjust.

The positive adjustment accounts for the
lower attenuation of vibration in rock
compared to soil. It is generally more difficult
to excite vibrations in rock than in soil at the
source.
50 ft
100 ft
150 ft
200 ft
+2 dB
+4 dB
+6 dB
+9 dB
Coupling to
building
foundation
Wood -Frame Houses
1-2 Story Masonry
3-4 Story Masonry
Large Masonry on Piles
Large Masonry on Spread
Footings
Foundation in Rock
-5 dB
-7 dB
-I0 dB
-10 dB
-13 dB
0 dB
In general, the heavier the building
construction, the greater the coupling loss.

In addition to the comments in Table 6-12, use the following guidelines to select the appropriate adjustment factors.
• Track Structure — The weight and size of a transit structure affects the vibration radiated by that structure. In general, vibration levels are lower for heavier transit structures. Therefore, the vibration levels from a cut -and -cover concrete double -box subway can be assumed to be lower than the vibration from a lightweight concrete -lined bored tunnel.

The vibration from elevated structures is lower than from at -grade track because of the mass and damping of the structure and the extra distance that the vibration must travel before it reaches the receiver.

Elevated structures in AGT applications are sometimes designed to bear on building elements. This is a special case and may require detailed design considerations.

The adjustments in this category are not additive; apply the greatest applicable value only.

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• Ground -Borne Propagation Effects — Geologic Conditions — Although it is known that geologic conditions have a considerable effect on the vibration levels, it is rarely possible to develop more than a general understanding of the vibration propagation characteristics for a General Vibration Assessment. One of the challenges with identifying the cause of efficient propagation is the difficulty in determining whether higher than normal vibration levels are due to geologic conditions or due to special source conditions (e.g., rail corrugations or wheel flats).

Some geologic conditions are repeatedly associated with efficient propagation. Shallow bedrock, less than 30 ft below the surface, is likely to have efficient propagation. Soil type and stiffness are also important factors in determining propagation characteristics. In particular, stiff, clayey soils, consolidated sand, gravel, and glacial till can be associated with efficient vibration propagation. Investigation of soil boring records can be used to estimate depth to bedrock and the presence of problem soil conditions.

A conservative approach would be to use the I 0 -dB adjustment for efficient propagation for areas where efficient propagation is likely.

However, this adjustment can greatly overstate the potential for vibration impact where efficient propagation is not present and should be applied using good judgment. Review available geological data and any complaint history from existing transit lines and major construction sites near the transit corridor to identify areas where efficient propagation is possible. If there is reason to suspect efficient propagation conditions, conduct a Detailed Vibration Analysis during the engineering phase and include vibration propagation tests at the areas with potential for efficient propagation.
• Track Structure and Geologic Conditions — Examples
▪ Subway
For a subway, determine if the subway will be founded in bedrock.

Bedrock is considered to be hard rock. It is usually appropriate to consider soft siltstone and sandstone to be more like soil than hard rock. Whether a subway is founded in soil or rock can make a I5 - dB difference in the vibration levels.

When a subway structure is founded in rock, include the following Track Structure and Ground -borne Propagation Effects adjustments from Table 6-12:
— Type of Transit Structure adjustment: Rock -based — 15 dB — Geologic Conditions adjustment: Propagation in rock layer for the appropriate distance.

This adjustment increases with distance because vibration attenuates more slowly in rock than in the soil used as a basis for the reference curve.
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vibration propagation results in vibration levels approximately I O dB higher than typical levels. This more than doubles the potential impact zone for ground -borne vibration.
• Ground -Borne Propagation Effects — Coupling to Building Foundation — Since annoyance from ground -borne vibration and noise is an indoor phenomenon, the effects of the building structure on the vibration must be considered. Wood -frame buildings, such as typical residential structures, are more easily excited by ground vibration than heavier buildings. In contrast, large masonry buildings with spread footings have a low response to ground vibration.

When a building foundation is directly on the rock layer, there is no coupling loss due to the weight and stiffness of the building. Use the standard coupling factors based on building type if there is at least a 10 - foot layer of soil between the building foundation and the rock layer. 2c. Apply receiver adjustments to the base curve using Table 6- 13 and the descriptions below to account for the project -specific receiver characteristics.

The data in Table 6-13 is applicable when the building structural features are known.

For more generic cases that do not have detailed information on individual buildings, use a conservative approach and apply the following adjustments to predict indoor vibration based on the outdoor vibration, instead of using the adjustments in Table 6-13:(43)(50)
• Light -weight, wood -frame construction I st floor: +3 dB • Light -weight, wood -frame construction 2nd and 3rd floors: +6 dB • Large buildings: 0 dB
• Small masonry buildings: +3 dB
Table 6-I3 Receiver Adjustment Factors for Generalized Predictions of GB Vibration and Noise Receiver
Factor
Adjustment to
Propagation Curve
Comment
Floor -to -floor
attenuation
I to 5 floors
above grade
5 to 10 floors
above grade
-2 dB/floor
- I dB/floor
This factor accounts for dispersion and attenuation
of the vibration energy as it propagates through a
building starting with the first suspended floor.'
Amplification
due to
resonances of
floors, walls,
and ceilings
+6 dB
The actual amplification will vary greatly depending
on the type of construction. The amplification is
lower near the wall/floor and wall/ceiling
intersections.
* Floor -to -floor attenuation adjustments for the first floor assume a basement.

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In addition to the comments in Table 6- 13, use the following guidelines to select the appropriate adjustment factors. Note that receiver adjustments are additive. ■ Vibration generally reduces in level as it propagates through a building.

As indicated in Table 6-I 3, a I- to 2 -decibel attenuation per floor is typically appropriate.
• Resonances of the building structure, particularly the floors, will cause some amplification of the vibration. Consequently, for a wood -frame structure, the building -related adjustments nearly cancel out. Example:

All adjustments for the first floor assuming a basement are: -5 dB for the coupling loss; -2 dB for the propagation from the basement to the first floor; and +6 dB for the floor amplification. The total adjustment in this case is -I dB.
2d. Apply adjustments to the final adjusted curve using Table 6- I4 and the descriptions below to convert ground -borne vibration levels to ground -borne noise levels.

Table 6-I4 Conversion to Ground -borne Noise
Conversion to Ground -borne Noise
Peak frequency of ground vibration:

Use these adjustments to estimate the A -
Low frequency ( 60 Hz)
-20 dB
Estimate the levels of radiated noise using the average vibration amplitude of the room surfaces (floors, walls, and ceiling), and the total acoustical absorption in the room.

The un-weighted sound pressure level is approximately 5 dB(37)(43) less than the vibration velocity level when the velocity level is referenced to I x 10-6 inches/sec; but for a better estimate, it is necessary to consider general frequency ranges. Since ground -borne noise is A -weighted, the adjustments vary by frequency range, as described below. See Appendix B. I .4. I for more information on A -weighting.

To select the appropriate adjustment, classify the frequency characteristics according to the guidelines below.

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■ Low Frequency ( 60 Hz) — High -frequency characteristics can be assumed for the following conditions:
ci Subways with the transit structure founded in rock
• Subways, when there is very stiff, clayey soil
Step 3: Inventory of Vibration Impact
Take inventory of vibration -sensitive land uses with impact and determine if a Detailed Vibration Analysis is required.

Compare the projected vibration levels, including all appropriate adjustments in Section 6.4, Step 2, to the criteria to determine if impact from ground -borne vibration or noise is likely. Note that for any transit mode, variation in vibration levels under apparently similar conditions is not uncommon. In the General Vibration Assessment, it is preferable to make a conservative assessment of the impact and include buildings that may ultimately not be subject to impact.

The standard curves in Section 6.4, Step I, represent the upper range of vibration levels from well -maintained systems. Although actual levels fluctuate widely, it is rare that ground -borne vibration will exceed these curves by more than I or 2 dB unless there are extenuating circumstances such as wheel- or running -surface defects. However, because actual levels of ground -borne vibration will sometimes differ substantially from the projections, use the following guidelines to interpret vibration impact:
■ Projected vibration is below the impact threshold — Vibration impact is unlikely, and the environmental document should state this. • Projected ground -borne vibration is 0 to 5 dB greater than the impact threshold — There is a strong chance that actual ground -borne vibration levels will be below the impact threshold. The environmental document should report impact at these locations as exceeding the applicable threshold, present possible mitigation measures and costs, and commit to conducting more detailed studies to refine the vibration impact analysis during the engineering phase. During the Detailed Vibration Analysis, determine appropriate mitigation, if necessary. A site -specific Detailed Vibration Analysis may show that vibration impacts will not occur and control measures are not needed.

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■ Projected ground -borne vibration is 5 dB or greater than the impact threshold — Vibration impact is probable and Detailed Vibration Analysis must be conducted during the engineering phase to determine appropriate vibration control measures. The environmental document should report impact at these locations as exceeding the applicable threshold, present possible mitigation measures and costs, and commit to conducting more detailed studies to refine the vibration impact analysis during the engineering phase. During the Detailed Vibration Analysis, determine appropriate mitigation, if necessary. A site -specific, Detailed Vibration Analysis may show that very costly vibration mitigation must be incorporated into the project to eliminate the impacts.

FTA recommends the reporting of a vibration level as a single value and not as a range, as ranges tend to confuse the interpretation of impact.

Express the results of the General Vibration Assessment in terms of an inventory with the following components:
• Include all vibration -sensitive land uses as identified in the Vibration Screening Procedure.
• Organize the inventory according to the categories described in Table 6-8.
• Include information on potentially feasible mitigation measures to reduce vibration to acceptable levels based on the generalized reduction estimates provided in this section. To be considered feasible, the measure or combination of measures must provide at least a 5 -dB reduction of the vibration levels and be reasonable in terms of cost.

These potential mitigation measures are considered preliminary. Final vibration mitigation measures can only be specified after a Detailed Vibration Analysis has been done; see Section 6.5 for more information. Vibration control is frequency -dependent; therefore, specific recommendations of vibration control measures can only be made after evaluating the frequency characteristics of the vibration.

Example 6- I General Vibration Assessment — LRT
General Vibration Assessment for an LRT project
The hypothetical project is a LRT system that operates at 40 mph on at -grade, ballast and tie track with welded rail. The first floor of houses is at 125 ft from the LRT tracks and there is efficient propagation through the soil.

The houses are constructed with wood frames. The houses will be exposed to 260 train passbys per day.

Calculate the ground -borne vibration and assess for impact.

Select Base Curve for Ground Surface Vibration
Determine the appropriate base curve and the RMS velocity level (4).

According to Table 6-9, the Rapid Transit or Light Rail Vehicles curve is appropriate.

L„ = 65 VdB at 125 ft for this curve at 50 mph
Apply Adjustments
Apply the appropriate source adjustments using Table 6- I I.

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40 Source Speed Adjustment = 20 log (50) = —1.9 dB
L„=65-1.9=63.1VdB
Apply the appropriate path adjustments using Table 6-12.

Efficient propagation = +10 dB
Coupling to building foundation (wood frame) = —5 dB
= 63.1 + 10 - 5 = 68.1 VdB
Apply the appropriate receiver adjustments using Table 6-I 3.

Amplification due to resonance of floor = +6 dB
First floor attenuation = —2 dB
L„ = 68.1+6-2 = 72.1 VdB
Assess for Impact
Because there are more than 70 events per day, this project is in the Frequent Events category (Table 6-2). For category 2 land uses (residences) with frequent events, the impact criteria is 72 VdB (Table 6-3). Therefore, according to the General Vibration Assessment, there is potential for impact and a Detailed Vibration Analysis should be completed.

6.5 Evaluate Impact: Detailed Vibration Analysis
Evaluate for impact using the Detailed Vibration Analysis procedure, if appropriate (Section 6. I).

The goal of the Detailed Vibration Analysis is to use all available tools to develop accurate projections of potential ground -borne vibration impact and when necessary, to design mitigation measures. A Detailed Vibration Analysis requires developing estimates of the frequency components of the vibration signal, usually in terms of I/3 -octave -band spectra. The analytical techniques for solving vibration problems are complex, and the technology continually advances. Therefore, the approach presented in this section focuses on the key steps for these analyses. The key elements of the Detailed Vibration Analysis procedure and recommended steps are described below.

The methods in this section generally assume a steel-wheel/rail system. The procedures could be adapted to bus systems. However, this is rarely necessary because vibration impact is very infrequent with rubber -tired transit.

In general, when situations arise that are not explicitly covered in the Detailed Vibration Analysis, professional judgment may be used to extend these methods to cover these unique cases, when appropriate. Appendix G provides information on developing and using non-standard modeling procedures.

Step I : Characterize Existing Vibration Conditions
Conduct measurements to survey and document the existing vibration conditions.

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document general background vibration in the project corridor. Because the existing environmental vibration is usually below human perception, a limited vibration survey is sufficient even for a Detailed Vibration Analysis.

It is particularly valuable to survey vibration conditions at sensitive locations for the following reasons:
• To obtain valuable information on the true sensitivity of the activity to external vibration and obtain a reference condition under which vibration is not problematic.
• To document that existing vibration levels are above or below the normal threshold of human perception for the existing condition. • To document levels of vibration created by existing rail lines. If vibration from an existing rail line is higher than the proposed train, there may not be impact even if the standard impact criteria are exceeded. • To use existing vibration sources to characterize propagation. Existing vibration sources such as freight trains, industrial processes, quarrying operations, or normal traffic can be used to characterize vibration propagation. Carefully designed and performed measurements may eliminate the need for more complex propagation tests. See Appendix G for information on using non-standard modeling procedures. • To identify the potential for efficient vibration propagation. If a measurement site has existing vibration approaching the range of human perception (e.g., the maximum vibration velocity levels are greater than about 65 VdB), then this site should be carefully evaluated for the possibility of efficient vibration propagation.

Conduct measurements to characterize existing vibration conditions. The goal of most ambient vibration measurements is to characterize the rms vertical vibration velocity level at the ground surface. In almost all cases, it is sufficient to measure only vertical vibration and ignore the transverse components of the vibration. Although transverse components(51) can transmit vibration energy into a building, the vertical component typically dominates.

I a. Choose Measurement Locations — Conduct outdoor and/or indoor measurements to characterize existing vibration conditions, as appropriate, for the project. Although ground -borne vibration is almost exclusively a problem inside buildings, it is generally recommended to perform measurements outdoors because equipment inside the building may cause more vibration than exterior sources. Additionally, the building structure and the resonances of the building can have strong effects on the vibration that are difficult to predict. It can also be important to measure and document those indoor sources of vibration. These indoor sources may cause vibration greater than that due to external sources like street traffic or aircraft overflights. When measuring (indoor) floor vibration, take measurements near the center of a floor span where the vibration amplitudes are the highest.

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I b. Measurement Considerations
■ Site selection — Selecting sites for an ambient vibration survey requires good judgment. Sites selected to characterize a transit corridor should be distributed along the entire project where potential for impacts have been identified and should be representative of the types of vibration environments found in the corridor. This would commonly include:
• Measurements in quiet, residential areas removed from major traffic arterials to characterize low -ambient vibration areas; • Measurements along major traffic arterials and highways or freeways to characterize high -ambient vibration areas;
• Measurements in any area with vibration -sensitive activities; and • Measurements at any major existing source of vibration such as railroad lines.
• Transducer placement — Place the transducers near the building setback line. For ambient measurements along railroad lines, it is recommended to include:
• Multiple sites at several distances from the rail line at each site, and • 4 to 10 train passbys for each test.

Because of the irregular schedule for freight trains and the low number of operations each day, it is often impractical to perform tests at more than two or three sites along the rail line or to measure more than two or three passbys at each site.

Rail type and condition strongly affect the vibration levels.

Consequently, it is important to inspect the track to locate any switches, bad rail joints, corrugations, or other factors that could be responsible for higher than normal vibration levels. Locations with these kinds of irregularities should be represented in addition to locations with rail in better condition.
• Transducer mounting methods — The way a transducer is mounted can affect the measured levels of ground -borne vibration. ▪ Straightforward methods of mounting transducers on the ground surface or on pavement are adequate for vertical vibration measurements for the frequencies of concern for ground -borne vibration (less than about 200 Hz).
• Quick -drying epoxy, clay, or beeswax can be used to mount transducers to smooth paved surfaces or metal stakes driven into the ground.
▪ Rough concrete or rock surfaces require special mountings. One approach is to use a liberal base of epoxy to attach small aluminum blocks to the surface, and then mount the transducers on the aluminum blocks.
• When in doubt, review the specific transducer documentation and discuss additional mounting guidance with the transducer manufacturer.

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I c. Existing Vibration Characterization — The appropriate methods of characterizing ambient vibration are dependent on the type of information required for the analysis. Consider the following when characterizing the existing vibration:
• Ambient vibration — Ambient vibration is usually characterized with a continuous 10- to 30 -minute measurement of vibration. The rms velocity level of the vibration velocity level over the measurement period provides an indication of the average vibration energy. The rms velocity level over the measurement period is typically equivalent to a long averaging time rms level.
• Specific events — Characterize specific events such as train passbys by the rms level over the time that the train passes by. If the locomotives produce vibration levels more than 5 dB higher than the passenger or freight cars, obtain a separate rms level for the locomotives. The locomotives can usually be characterized by the Lmax during the train passby. The rms averaging time or time constant should be I second when determining Lmax. In some cases, it may be adequate to characterize the train passby using Lmax, which is simpler to obtain than the rms averaged over the entire train passby.
• Spectral analysis — Perform a spectral analysis of vibration propagation data. For example, if vibration transmission of the ground is suspected of having particular frequency characteristics, use I /3 -octave band charts to describe vibration behavior. Narrowband spectra also can be valuable, particularly for identifying discrete frequency components and designing specific mitigation measures.

Note that it is preferred to characterize existing vibration in terms of the rms velocity level instead of the peak PPV, which is commonly used to monitor construction vibration. As discussed in Section 5.1, rms velocity is considered more appropriate than PPV for describing human response to building vibration.

Step 2: Estimate Vibration Impact
Estimate ground -borne vibration and noise at sites where significant impact is probable and assess for impact.

Predicting ground -borne vibration associated with a transportation project continues to be a developing field. Because ground -borne vibration is a complex phenomenon that is difficult to model and predict accurately, most projection procedures that have been used for transit projects rely on empirical data.

The procedure described in this section is based on site -specific tests of vibration propagation. This procedure was developed under a FTA-funded research contract(52) and is recommended for detailed evaluations of ground - borne vibration. Other approaches to a prediction procedure, such as finite element methods, can be used. See Appendix G for information on using non- standard modeling procedures.

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Overview of Prediction Procedure — This procedure was developed to allow the use of data collected in one location to accurately predict vibration levels in another site where the geologic conditions may be completely different.

The procedure is based on transfer mobility. Transfer mobility is the complex velocity response produced by a point force as a function of frequency. It represents the relationship between a vibration source that excites the ground and the resulting vibration of the ground surface. It is a function of both frequency and distance from the source. The analyses in this manual focus on transfer mobility magnitude, which is the magnitude for the velocity relative to the force without reference to phase. The transfer mobility level is the level in decibels relative to I E-6 in/lb-s.

The transfer mobility measured at an existing transit system is used to normalize ground -borne vibration data and remove the effects of geology. The normalized vibration is referred to as the force density. Force density is the force per root distance along the track in Ib/ft"2. The force density can be combined with transfer mobility measurements at vibration -sensitive sites along a new project to develop projections of future ground -borne vibration.

The transfer mobility between two points completely defines the composite vibration propagation characteristics between the two points. In most practical cases, receivers are close enough to the train tracks that the vibration cannot be considered as originating from a single point. Therefore, the vibration source must be modeled as a line -source. Consequently, the point transfer mobility must be modified to account for a line -source. The subsequent line -source transfer mobility is given in units of decibels relative to I e-6 in/s/Ib/sgrt(ft).

The prediction procedure considers ground -borne vibration to be divided into several basic components described below and shown in Figure 6-5. • Excitation Force (Force Density) — The vibration energy is created by oscillatory and impulsive forces. Steel wheels rolling on smooth steel rails create random oscillatory forces. When a wheel encounters a discontinuity such as a rail joint, an impulsive force is created. The force excites the transit structure, such as the subway tunnel or the ballast for at -grade track.

In the prediction method, the combination of the actual force generated at the wheel/rail interface and the vibration of the transit structure are usually combined into an equivalent force density level. The force density level is the level in decibels of the force density relative to I Ib/ft1/2 and describes the force that excites the soil/rock surrounding the transit structure.
• Vibration Propagation (Transfer Mobility) — The vibration of the transit structure causes vibration waves in the soil that propagate away from the transit structure. The vibration energy can propagate through the soil or rock in a variety of wave forms. All ground vibration includes shear and compression waves. Rayleigh waves (49) are also created and propagate along the ground surface. These Rayleigh waves can be a FEDERAL TRANSIT ADMINISTRATION 153

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major carrier of vibration energy. The mathematical modeling of vibration is complicated when there are soil strata with different elastic properties, which is common. As indicated in Figure 6-5, the propagation through the soil/rock is modeled using the transfer mobility, which is usually determined experimentally.

The combination of the force density level and the transfer mobility is used to predict the ground- surface vibration. This is the major difference from the General Vibration Assessment, which generalizes estimates of the ground -borne vibration.
• Building Vibration — When the ground vibration excites a building foundation, it sets the building into vibratory motion and vibration waves propagate throughout the building structure. The interaction between the ground and the foundation causes some reduction in vibration levels. The amount of reduction is dependent on the mass and stiffness of the foundation. The more massive the foundation, the lower the response to ground vibration. As the vibration waves propagate through the building, they can create vibration that can be felt and cause windows and household items to rattle.
• Audible Noise — In addition to vibration that can be felt, the vibration of room surfaces radiates low -frequency sound that may be audible. The sound level is affected by the amount of acoustical absorption in the receiver room.

Ground surface
vibration
Vibration of
floors & walls,
possible feelable
vibration
Audible ground -
borne noise
Oscillatory or
impulsive force
Track fixation
4 Track support
Track structure
Propagation through
soilirock to soil surface
and building foundations
Building foundation
Propagation through
building structure
Radiation of sound by
vibrating room surfaces
Acoustical absorption
in room
Excitation Force
(Force Density)
Vibration Propagation
(Transfer Mobility)
Building Vibration
Audible Noise
Figure 6-5 Ground -Borne Vibration and Noise Model
A fundamental assumption of the prediction approach outlined in this section is that the force density, transfer mobility, and the building coupling to the ground are all independent factors. The following equations are the basis for the FEDERAL TRANSIT ADMINISTRATION 154

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prediction procedure, where all of the quantities are one-third octave band spectral levels in decibels with consistent reference values:
where:

Lv = FDL + LSTM + Cbuild
LA = Lv + Krad + KA-wt
Lv
FDL
LSTM
Cbuild
LA
Krad
KA-wt
Eq. 6-5
Eq. 6-6
= rms vibration velocity level in VdB
= force density level in dB for a line vibration source such as a train
= line -source transfer mobility level in dB from the tracks to the sensitive site
= adjustments to account for ground -building foundation interaction and attenuation of vibration amplitudes as vibration propagates through buildings
= A -weighted sound level
= adjustment to account for conversion from vibration to sound pressure level including accounting for the amount of acoustical absorption inside the room. A value of -5 dB can be used for Krad for typical residential rooms when the decibel reference value for l—, is I micro in/sec (37)(50)
= A -weighting adjustment at the I/3 -octave band center frequency All of the quantities given above are functions of frequency, and the standard approach is to develop projections on a I/3 -octave band basis using the average values for each I /3 -octave band. The end results of the analysis are the I/3 - octave band spectra of the ground -borne vibration and the ground -borne noise.

The spectra are then compared to the vibration criteria for the Detailed Vibration Analysis. The A -weighted ground -borne noise level can be calculated from the vibration spectrum and compared to the criteria. This more detailed approach differs from the General Vibration Assessment, where the overall vibration velocity level and A -weighted sound level are predicted without any consideration of the particular frequency characteristics of the propagation path.

The key steps in obtaining quantities for Eq. 6-5 and Eq. 6-6 are presented in the following steps and include:

Step 2a. Estimate force density
Step 2b. Measure the point -source transfer mobility
Step 2c. Estimate line -source transfer mobility
Step 2d. Project ground -borne vibration and ground -borne noise 2a. Estimate Force Density — The estimate of force density can be based on previous measurements or a special test program can be designed to measure the force density at an existing facility.

If no suitable measurements are available, conduct testing at a transit facility with equipment similar to the planned vehicles. Adjustments for factors such as train speed, track support system, and vehicle suspension may be needed to match the force density to the conditions at a specific site. Review the report FEDERAL TRANSIT ADMINISTRATION 155

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"State -of- the -Art Review: Prediction and Control of Ground -Borne Noise and Vibration from Rail Transit Trains" (41) for examples of appropriate adjustments.

Force density is not a quantity that can be measured directly; it must be inferred from measurements of transfer mobility and train vibration at the same site. To derive force density, the best results are achieved by deriving line -source transfer mobility from a line of impacts. The standard approach is to average the force density from measurements at three or more positions at one site. If feasible, it is recommended to take measurements at more than one site and at multiple speeds.

If no suitable measurements are available, see Steps 2b and 2c for guidelines on obtaining line -source transfer mobility.

The force density for each I/3 -octave band is as follows:

FDL = L„ — LSTM Eq. 6-7
where:

FDL
L„
LSTM
= force density level in dB
= measured train ground -borne vibration
level in VdB
= line -source transfer mobility level in dB
Figure 6-6 shows example trackbed force densities in decibels relative to I lb/(ft)1/2. These force densities were developed from measurements of vibration from heavy and LRT vehicles and represent an incoherent line of vibration force equal to the length of transit trains. This figure provides a comparison of the vibration forces from heavy commuter trains and LRT vehicles with different types of primary suspensions, illustrating the range of vibration forces commonly experienced in a transit system. A force density of a vehicle includes the characteristics of its track support system at the measurement site. Adjustments must be applied to the force density to account for differences between the facility where the force density was measured and the new system being analyzed.

Figure 6-7 shows typical force densities for rail transit vehicles at 40 mph on ballast and tie tracks, which are approximately within the tolerances shown in Figure 6-6. The force densities should be applied very carefully for other track types and speeds. The embedded tracks, although considerably stiffer than ballast and tie tracks, are expected to show similar force density levels.(53) The curves in Figure 6-7 should also be applied with caution for newer generations of light rail vehicles as well as vehicles that utilize direct fixation tracks. The preferred approach for vibration predictions would be to perform force density measurements at a system with vehicles and operations that are similar to those of the future project.

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Force Density, dB re 1 lb/(ft)112
7-
IM
Commuter Rail Range
Commuter Rail Average
Light Rail Range
---- Light Rail Average
1/3 Octave Band Center Frequency, Hz
I I I
I-----`----4-----I-----I
125
1 Figure 6-6 Typical Force Densities for Rail Transit Vehicles, 40 mph 250
60 —
P.! 50
Rail Average
B&T Tracks
Rail Max for
Tracks
Rail Min for
Tracks
Light
for
V =
—Light
B&T
Light
40 _
—
—
B&T
''.------ \
.'
----------\_.„..____
:orce D
I"
5 8
16 31.5 63
113 Octave Band Frequency, Hz
125
Figure 6-7 Typical Force Densities for LRT Vehicles, 40 mph 250
2b. Measure Point -Source Transfer Mobility — Using the appropriate instrumentation, measure point -source transfer mobility for sources with short lengths, such as buses or single car vehicles or columns supporting elevated structures. For longer vehicles, see Section 2c for a discussion of measuring line - source transfer mobilities.

The test procedure to measure point -source transfer mobility consists of impacting the ground by dropping a heavy weight and measuring the force into the ground and the response at several distances from the impact. Other excitation sources may include swept sine, sine -dwell, random vibration, and maximum length sequence. The goal of the test is to create vibration pulses that FEDERAL TRANSIT ADMINISTRATION 157

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travel from the source to the receiver using the same path that will be taken by the transit system vibration.

Figure 6-8 illustrates the field procedure for measuring both at -grade and subway testing of transfer mobility. A weight is dropped from a height of 3 to 4 ft onto a force transducer. The responses of the force and vibration transducers are recorded on a multichannel recorder for later analysis in the laboratory. An alternative approach is to set up the analysis equipment in the field and capture the signals directly. This complicates the field testing, but eliminates the laboratory analysis of recorded data.
liDropped Weight
Load Cell
At -Grade Testing
Bore hole to
depth of
subway
Impact
Load Cell
Subway Testing
a Accelerometers
Figure 6-8 Test Configuration for Measuring Transfer Mobility When the procedure is applied to subways, the force must be located at the approximate depth of the subway. This is done by drilling a bore hole and locating the force transducer at the bottom of the hole. The tests are usually performed while the bore holes are drilled to allow for the use of the soil - sampling equipment on the drill rig for the transfer mobility testing. The force transducer is attached to the bottom of the drill string and lowered to the bottom of the hole. A standard soil sampling hammer is used to excite the ground; typically, a I 40 -pound weight is dropped I8 inches onto a collar that is attached to the drill string. The force transducer must be capable of operating under water if the water table is near the surface or a slurry drilling process is used.

Standard signal -processing techniques are used to determine the transfer function (frequency response function) between the exciting force and the resultant ground -borne vibration. Numerical regression methods are used to combine a number of two -point transfer functions into a smooth point -source transfer mobility level that represents the average vibration propagation characteristics of a site as a function of both distance from the source and FEDERAL TRANSIT ADMINISTRATION 158

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frequency. The transfer mobility level is usually expressed in terms of a group of I/3 -octave band transfer mobility levels. Figure 6-9 is an example of point - source transfer mobility levels from a series of tests at the Transportation Technology Center in Pueblo, Colorado.(50)(54)(55)(56)(57) 20 10
CO
13 ▪ p
Qf
a� - -10
-20
N
▪ -30
f
I -
I
y , . .. '� . -..--,---
---,r'•.' tip I!
' � ti I < I
• r._ •.� i i eta 'r
•
1 .� ''1 I
1 •` II
I •
1 '
'f.. I i' .,:200 f1, Ie . 150 ft.
• '300 ft\ I -.i
J
r ----s----7
25 ft
50 ft
L
-. 100ft
J
8 16 31.5 63
1/3 Octave Band Center Frequency
125 250
Figure_6-9 Example of Point -Source Transfer Mobility
Instrumentation
Performing a transfer mobility test requires specialized equipment, which is generally available from commercial sources. Typical instrumentation for field- testing and laboratory analysis of transfer mobility is shown in Figure 6-10.

A load cell can be used as the force transducer. The force transducer should be capable of impact loads of 5,000 to 50,000 pounds depending on the hammer used for the impact. For borehole testing, the load cell must be hermetically sealed and capable of being used at the bottom of a 30- to I 00 -foot -deep hole partially filled with water.

Either accelerometers or geophones can be used as the vibration transducers.

Geophones should be carefully mounted so that they are vertical. The requirement is that the transducers with the associated amplifiers be capable of accurately measuring levels of 0.0001 in/sec at 40 Hz and have a flat frequency response from 6 Hz to 400 Hz. Data should be acquired with a digital acquisition system with a flat frequency response over the range of 6 to 400 Hz.

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Field Equipment
Dropped Weight
or
Tactile Transducer
Force Transducer
Accelerometers
Signal Conditioning
and
Amplification
Data Acquisition
System
Data Acquisition
System
Laboratory Equipment
Force Signal
Accelerometer Signals
Acceleration
Signal
Integrator
(optional)
Monitoring
Equipment
r
■
■
Spectrum
Analyzer
r-)
)(Headphones -
Velocity
Signal
Spectrum
Analyzer
or
Signal Processing
Software
Figure 6-10 Equipment Required for Field Testing and Laboratory Analysis A narrowband spectrum analyzer or signal -processing software can be used to calculate the transfer function and coherence between the force and vibration data. The analyzer must be capable of capturing impulses from at least two channels to calculate the frequency spectrum of the transfer function between the force and vibration channels. All transfer functions should include the average of at least 20 impulses. Time averaging of the impulses will provide substantial signal enhancement, which is usually required to accurately characterize the transfer function. Signal enhancement is particularly important when the vibration transducer is more than 100 ft from the impact.

Alternative methods of determining transfer mobility may be used, provided that these techniques have been demonstrated to provide the same results as the conventional weight -drop method over the frequency range of 6 Hz to 400 Hz. See Appendix G for information on developing and using non-standard procedures. These methods may include using other impulse -response measurement systems involving the use of shakers or electro-mechanical actuators, stimuli such as sweeps or maximum length sequences (MLS), and various signal processing techniques. A forthcoming ANSI Standard will describe in detail the procedures, methodologies, and reporting requirements for performing ground -borne vibration propagation measurements.

The transfer function can be calculated with either a spectrum analyzer or signal -processing software. Note that transfer functions should include the average of at least 20 impulses. Specialized multi -channel spectrum analyzers have built-in capabilities for computing transfer functions and are computationally efficient. However, signal -processing software can offer more FEDERAL TRANSIT ADMINISTRATION 160

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flexibility in analyzing data signals and allows the use of different digital signal processing methods. Typical measurement programs involve acquisition of data in the field and later processing of the information in a laboratory. However, recent advances in instrumentation and signal -processing software allow data to be collected and analyzed while in the field.
2c. Estimate Line -Source Transfer Mobility — Estimate line -source transfer mobility for long sources such as multi -car trains. Line -source transfer mobilities are used to normalize measured vibration velocity levels from train passbys and to obtain force density. Two different approaches can be used to develop estimates of line -source transfer mobility. The first consists of using lines of transducers and the second consists of a line of impact positions.

Option A: Lines of Transducers — Develop line -source transfer mobility curves from tests using one or more lines of transducers as shown in Figure 6- I I and described below.

Narrowband Transfer Mobility
1/3 Octave Band Transfer Mobility
(one spectrum for each distance at each site)
Best -fit Curve of Transfer Mobility
as a Function of Distance
(one for each 1/3 octave band)
Line -Source Transfer Mobility
(estimated using numerical integration
of point source transfer mobility)
2 C �
Frequency
Frequency
Distance
47"Line Source
Point -- —
Source
Distance
Figure 6-1 I Analysis of Transfer Mobility
Ai. Obtain the narrowband transfer function between source and receiver at each measurement position. There should be a minimum of four distances in any test line. Because of the possibility of local variations in propagation characteristics, two or more lines should be used to characterize a site if possible. A total of I 0 to 20 transducer positions are often used to characterize a site.

Aii. Calculate the equivalent I/3 -octave band transfer functions, generally between 6 and 400 Hz. This reduces each spectrum to 15 numbers. As shown in Figure 6 -I I, the I/3 -octave band spectrum is much smoother than the narrowband spectrum.

Aiii. Calculate a best -fit curve of transfer mobility as a function of distance for each I /3 -octave band. When analyzing a specific site, the best -fit curve will be FEDERAL TRANSIT ADMINISTRATION 161

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based on I 0 to 20 points. Up to several hundred points could be used to determine average best -fit curves for a number of sites.

Aiv. Apply the best -fit curve to the vibration sources. The I /3 -octave band best -fit curves can be directly applied to point vibration sources. Buses can usually be considered point -sources, as can columns supporting elevated structures. However, for a line vibration source such as a train, numerical integration must be used to calculate the equivalent line -source transfer mobility. The numerical integration procedures are detailed in the TRB publication: "A Prediction Procedure for Rail Transportation Ground -Borne Noise and Vibration."(50)
Option B: Line of Impulses — This second procedure for estimating line - source transfer mobility is best for detailed assessment of specific vibration paths or specific buildings and is a more direct approach.

Bi. Measure multiple point -source transfer mobilities according to the procedures in Step 2b above. The vibration transducers are placed at specific points of interest and a line of impacts is used. For example, a I 50 -foot train might be represented by a line of I I impact positions along the track centerline at 15 -foot intervals (Figure 6-12).

Bii. Sum the point -source results using Simpson's rulexiii for numerical integration to calculate the line -source transfer mobility.

Figure 6-13 shows an example of line -source transfer mobilities that were derived from the point -source transfer mobilities shown in Figure 6-9. r
$C'
,yxm
Figure 6-I2 Schematic of Transfer Mobility Measurements Using a Line of Impacts xiii Simpson's rule is a method for approximating integrals.

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40 -a 30
0 20
sn
C 10
V
• o
Q
(!)1
i • -10
-20
L
S..
25 ft
r50 ft
8 ti r
\ . !200 ft N.
300 ft \ `•\
.
16 31,5 63
113 Octave Band Center Frequency, Hz
ft
�• 150 ft:
•\I
125 250
Figure 6-13 Example of Line -source Transfer Mobility
2d. Project Ground -Borne Vibration and Noise — Combine force density and line -source transfer mobility to project ground -borne vibration. Then, apply adjustment factors to estimate the building response to the ground -borne vibration and to estimate the A -weighted sound level inside buildings.

The propagation of vibration from the building foundation to the receiver room is very complex and dependent on the specific design of the building. Detailed evaluation of the vibration propagation would require extensive use of numerical procedures such as the finite element method. Such a detailed evaluation is generally not practical for individual buildings considered in this manual. If the detailed features of the individual buildings are available, the recommended procedure is to estimate the propagation of vibration through a building and the radiation of sound by vibrating building surfaces using simple empirical or theoretical models. The recommended procedures are outlined in the Handbook of Urban Rail Noise and Vibration Control.(44) The approach consists of adding the following adjustments to the I /3 -octave band spectrum of the projected ground -borne vibration:
• Building response or coupling loss — This adjustment represents the change in the incident ground -borne vibration due to the presence of the building foundation. The adjustments described in the handbook (44) are shown in Figure 6- I4. Note that the correction is zero when estimating basement floor vibration or vibration of at -grade slabs.

Measured values may be used in place of these generic adjustments. • Transmission through the building — The vibration amplitude typically decreases as the vibration energy propagates from the foundation through the remainder of the building. The general assumption is that vibration attenuates by I to 2 dB for each floor. • Floor resonances — Vibration amplitudes will be amplified because of resonances of the floor/ceiling systems. For a typical wood -frame FEDERAL TRANSIT ADMINISTRATION 163

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residential structure, the fundamental resonance is usually in the 15 to 20 Hz range. Reinforced -concrete slab floors in modern buildings will have fundamental resonance frequencies in the 20 to 30 Hz range. An amplification resulting in a gain of approximately 6 dB should be used in the frequency range of the fundamental resonance.
• Floor vibration and ground -borne noise — The projected floor vibration is used to estimate the levels of ground -borne noise. The primary factors affecting noise level are the average vibration level of the room surfaces and the amount of acoustical absorption within the room. The radiation adjustment is -5 dB for typical rooms, (37) (50) which gives:
where:

LA LIT +KA-wt-5
LA
L„
KA-wt
Eq. 6-8
= A -weighted sound level in a I /3 -octave band
= rms vibration velocity level in that band
= A -weighting adjustment at the I /3 -octave band center frequency
The A -weighted levels in the I /3 -octave bands are combined to produce the overall A -weighted sound level.
10 m 5
a a
-5
o
o -20
7 N
10 CC
5 • 0
-5
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a -10
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-20
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i

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a
16 31.5 63
113 Octave Band Center Frequency, Hz
125
Figure 6- 14 Foundation Response for Various Types of Buildings 254
Where detailed information on the structural features of individual buildings are unavailable and there are no site -specific data on outdoor to indoor propagation characteristics, the preferred approach is to apply a combined factor for the foundation response and the gain from floor resonances. Empirical data based on the TCRP D-12 Project from 34 measurement sites across 5 cities in North FEDERAL TRANSIT ADMINISTRATION 164

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America and other studies suggest that the average change in vibration from outdoor to indoor was 0 dB across all I/3 -octave bands with a standard deviation of approximately 5 to 6 dB in the 3 I.5 to 63 Hz frequency.(43)(48) Therefore, the recommended approach for predicting indoor vibration based on outdoor data is to use an adjustment of +3 to +6 dB for light -weight, wood - frame construction and use an adjustment of 0 dB for heavier buildings.

However, for buildings with high -vibration sensitivity or where there is concern regarding interference with vibration -sensitive equipment, it is advisable to measure the outdoor -indoor response of the building, using the process described in Section 2b or 2c, to determine the actual response of the foundation and building to vibration.

Step 3: Assess Vibration Impact
Take inventory of vibration -sensitive land uses with impact.

Assess vibration impact at each receiver of interest using the impact criteria in Section 6.3. Note that ground -borne vibration and noise levels that exceeded criteria in the General Vibration Assessment may not cause impact according to the more detailed procedures of the Detailed Vibration Analysis; in which case, mitigation is not required. But if projected levels still exceed the criteria, evaluate vibration mitigation measures using the spectra provided by the Detailed Vibration Analysis.

Step 4: Determine Vibration Mitigation Measures
Select practical vibration control measures that will be effective at the dominant vibration frequencies and compatible with the given transit structure and track support system.

The purpose of vibration mitigation is to minimize the adverse effects that the project ground -borne vibration and ground -borne noise will have on sensitive land uses. Because ground -borne vibration is not as common a problem as environmental noise, the mitigation approaches have not been as well defined. In some cases it may be necessary to develop innovative approaches to control the impact. See Appendix G for information on using non-standard methods.

Standard vibration control measures for rail transit systems are discussed in this step. Note that vibration control measures for rail transit systems are not always effective for freight trains.(xi') Bus systems rarely cause vibration impact, but if impact occurs, roadway roughness or unevenness caused by bumps, pot holes, expansion joints, or driveway transitions are usually the causes.

Smoothing the roadway surface is typically the recommended course of action.(xv)
xiv The heavy axle loads associated with freight rail are outside the range of applicable design parameters for vibration reduction on lighter rail transit systems. Plans to relocate existing railroad tracks closer to vibration -sensitive sites in order to accommodate a new rail transit line in the ROW must be carefully considered because it may not be possible to mitigate the increased vibration impact from freight trains.
xv In cases where a rubber -tired system runs inside a building, such as an airport people mover, vibration control may involve additional measures. Loading and unloading of guideway support beams may generate dynamic forces that transmit into the building structure. Special guideway support systems may be required, similar to the discussion below regarding floating slabs.

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Vibration reduction measures incur additional costs to a system. Some of the same treatments for noise mitigation can be considered for vibration mitigation.

Costs for noise control measures are documented in a report from the Transit Cooperative Research Program (TCRP).(31) Where applicable to vibration reduction, costs for noise abatement methods from that report are given in the following sections. These costs reflect the noise mitigation costs as of 1997 (unless otherwise noted), and should only be used as representative estimates when considering noise mitigation options. Current noise mitigation costs should be researched before decisions on noise mitigation options are finalized, and then they should be documented according to Section 8.

Mitigation of vibration impacts may involve treatments at the source, along the source -to -receiver propagation path, or at the receiver.

I a. Evaluate Source Treatments — The most effective vibration mitigation treatments are applied at the vibration source. This is the preferred approach to mitigation when possible. Possible source treatments include:
■ Preventative Maintenance — Effective maintenance programs are essential for controlling ground -borne vibration. Key vibration points are discussed below; see Section 4.5, Step 7 for more detailed information on the benefits of effective maintenance programs on controlling transit noise and vibration. While these are not mitigation measures in the traditional sense, and should not be included as mitigation in an environmental document, they can help to keep both noise and vibration levels at a "like -new" level or reduce both in systems with deferred maintenance.

Rail grinding is a particularly important practice for vibration mitigation for rail that develops corrugations. The TCRP report notes that periodic rail grinding results in a net savings per year on wheel and rail wear. Most transit systems contract out rail grinding, although some of the larger systems make the investment and do their own grinding. As mentioned in Section 4.5, Step 7, the typical rail grinding cost would be $ I000 to $7000 per grinding pass mile, with an additional investment of approximately $ I million for the equipment for a larger transit system to do its own grinding. ▪ Dramatic vibration reduction results can be achieved by removing wheel flats through wheel truing. As mentioned in Section 4.5, Step 7, a wheel truing machine costs approximately $ I million, including associated maintenance, materials, and labor costs.

The TCRP report figures a system with 700 vehicles would incur a yearly cost of $300,000 to $400,000 for a wheel truing program. • Profile grinding of the rail head in combination with a wheel truing program may be the most practical approach to controlling and reducing vibration and noise where such practices are not normally conducted. Profiles should be defined during the design phase and should be in place when system opens.(32) The cost of FEDERAL TRANSIT ADMINISTRATION 166

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wheel and rail profile matching may be incorporated in the new vehicle and new rail costs.

Rough wheels or rails can increase vibration levels by as much as 20 dB in extreme cases, negating the effects of even the most effective vibration control measures. Yet, it is rare that vibration control measures (such as those discussed below) will provide more than 15 to 20 dB attenuation. When there are ground -borne vibration impacts with existing transit equipment, the best vibration control measure often is to implement new or improved maintenance procedures. Grinding rough or corrugated rail and wheel truing to eliminate wheel flats and restore the wheel contour may provide considerable vibration reduction. Regular maintenance may replace the need to modify the existing track system, such as through adding floating slabs.
• Planning and Design of Special Trackwork — A large percentage of the vibration impact from a new transit facility is often caused by wheel impacts at special trackwork for turnouts and crossovers. When feasible, the most effective vibration control measure is to relocate the special trackwork to a less vibration -sensitive area. This may require adjusting the location by several hundred feet provided it will not have an adverse impact on the operation plan for the system. Careful review of crossover and turnout locations during the project development phase is an important step to minimizing potential for vibration impact.

Another approach is to use special devices (frogs) at turnouts and crossovers that incorporate mechanisms to close the gaps between running rails. Frogs with spring -loaded mechanisms and frogs with movable points can substantially reduce vibration levels near crossovers.

According to the TCRP report, a spring frog costs about $ 12,000, twice the cost of a standard frog. A movable point frog involves elaborate signal and control circuitry resulting in higher costs at approximately $200,000.
• Vehicle Specifications — The ideal rail vehicle with respect to minimizing ground -borne vibration should have the following characteristics:
• Low, unsprung weight
• Soft primary suspension
• A minimum of metal -to -metal contact between moving parts of the truck
• Smooth wheels that are perfectly round
A limit for the vertical resonance frequency of the primary suspension should be included in the specifications for any new vehicle. A vertical resonance frequency of 12 Hz or less is sufficient to control the levels of ground -borne vibration, although some have recommended the vertical resonance frequency be less than 8 Hz.

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• Special Track Support Systems — When the vibration assessment indicates that vibration levels will be excessive, the track support system is typically modified to reduce the vibration levels.

Floating slabs, resiliently supported ties, high -resilience fasteners, and ballast mats can be used to reduce the levels of ground -borne vibration.

To be effective, all of these measures must be optimized for the frequency spectrum of the vibration. Most of these relatively standard procedures have been successfully used on several subway projects.

Applications on at -grade and elevated track are less common. This is because vibration impact is less common for at -grade and elevated track. Note that the cost of these types of vibration control measures is a higher percentage of the overall construction costs for at -grade and elevated track, and exposure to the elements can require substantial design modifications.

Each major vibration control measure for track support is discussed below. Costs for these treatments are not covered by the TCRP report, but are given as estimates based on transit agency experience.

Resilient fasteners — Resilient fasteners are used to fasten the rail to concrete track slabs. Standard resilient fasteners are very stiff in the vertical direction, usually in the range of 200,000 lb/in, and do provide some vibration reduction compared to the rigid fastening systems used on older systems (e.g., wood half - ties embedded in concrete).

Special fasteners with vertical stiffness in the range of 30,000 lb/in may reduce vibration by as much as 5 to I O dB at frequencies above 30 to 40 Hz. These premium fasteners vary in cost and can be priced competitively when purchased in large quantities.

Ballast mats — A ballast mat consists of a rubber or other type of elastomer pad that is placed under the ballast. In general, the mat must be placed on a concrete pad to be effective. They will not be as effective if placed directly on the soil or the sub - ballast. Consequently, most ballast mat applications are in subway or elevated structures.

Ballast mats can provide 8 to 12 dB attenuation at frequencies above 25 to 30 Hz.(58) Ballast mats are often a good retrofit measure for existing tie -and -ballast track where there is vibration impact. Installed ballast mats cost approximately $ 180 per track -foot.

Undertie pads — Undertie pads (resiliently supported
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install or retrofit. Installed undertie pads cost approximately $260 per track -foot.

Resiliently supported ties — The resiliently supported tie system consists of concrete ties supported by rubber pads resting on top of a slab track or subway invert. The rails are fastened directly to the concrete ties using standard rail clips.

Resiliently supported ties provide vibration reduction in between 15 to 40 Hz, which is particularly appropriate for transit systems with vibration impact in the 20 to 30 Hz range.

A resiliently supported tie system costs approximately $400 per track -foot.

Floating slabs — Floating slabs can be very effective at controlling ground -borne vibration and noise and consist of a concrete slab supported on resilient elements such as rubber or a similar elastomer. Floating slabs are effective at frequencies greater than their single -degree -of -freedom vertical resonance frequency.

Floating slabs are among the most expensive vibration control treatments. A typical double -tie floating slab system costs approximately 4 times the cost of ballast and tie per track foot.

Examples of floating slabs include:
— Floating slabs used in Washington, DC; Atlanta, GA; and Boston, MA, were all designed to have a vertical
resonance in the 14 to 17 Hz range.
— A special system referred to as the double -tie system was first used in Toronto. It consists of 5 -foot -long slabs with four or more rubber pads under each slab.

This system was designed with a resonance frequency in
the 12 to 16 Hz rang3.
— Another special floating slab was used in San Francisco's Bay Area Rapid Transit (BART) system. It uses a
discontinuous precast concrete double -tie system with
a resonance frequency in the 5 to I 0 Hz frequency
range.
• Tire -derived aggregate (TDA) — TDA (shredded tires) consists of a layer of tire shreds wrapped in geotech fabric placed underneath the ballast on hard packed ground. This is a new, low- cost option that can provide reduction in vibration levels at frequencies above 25 Hz. This mitigation measure has proven to be effective for the Denver Regional Transportation District (RTD) light rail system as well as the Santa Clara Valley Transportation Authority (VTA) light rail system,(59) but the effective life of TDA has not been determined. Installed TDA costs approximately $260 per track -foot.
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such as using heavier rail, thicker ballast, or heavier ties can be expected to reduce the vibration levels. There also is some indication that vibration levels are lower with wood ties compared to concrete ties. But there is little confirmation that any of these approaches will make a substantial change in the vibration levels. • Operational Changes — The most effective operational change is to reduce the vehicle speed. Reducing the train speed by a factor of two will reduce vibration levels approximately 6 dB. Other operational changes include:

Use of equipment that generates the lowest vibration levels during the nighttime hours when people are most sensitive to vibration and noise.

Adjusting nighttime schedules to minimize movements in the most sensitive hours.

While there are tangible mitigation benefits from speed reductions and limits on operations during the most sensitive time periods, FTA does not generally accept speed reduction as a vibration mitigation measure for two important reasons: (I) speed reduction is unenforceable and negated if vehicle operators do not adhere to established policies, and (2) it is contrary to the purpose of the transit investment by FTA, which is to move as many people as possible as efficiently and safely as possible. FTA does not recommend limits on operations as a way to reduce vibration impacts.

I b. Evaluate Path Treatments — When vibration mitigation treatments cannot be applied at the vibration source or additional mitigation is required after treating the source, the next preferred placement of vibration mitigation is along the vibration propagation path between the source and receiver. Possible path treatments include:
• Trenches — Use of trenches to control ground -borne vibration is analogous to controlling airborne noise with noise barriers. This approach has not received much attention in the United States, but trenches could be a practical method for controlling transit vibration from at -grade track. A rule -of -thumb given by Richert and Ha11(60) is that if the trench is located close to the source, the trench bottom must be at least 0.6 times the Rayleigh wavelength below the vibration source.

For most soils, Rayleigh waves travel at around 600 ft/sec, which means that the wavelength at 30 Hz is 20 ft, requiring that a trench be approximately 15 ft deep to be effective at 30 Hz.

A trench can be effective as a vibration barrier if it is either open or solid. The Toronto Transit Commission tested a trench filled with Styrofoam to keep it open and reported successful performance over a period of at least one year. Solid barriers can be constructed with sheet piling or concrete poured into a trench.
• Buffer Zones — Expanding the rail ROW can be the most economical method of reducing the vibration impact by simply increasing the distance between the source and receiver. A similar approach is to FEDERAL TRANSIT ADMINISTRATION 170

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negotiate a vibration easement from the affected property owners (e.g., a row of single-family homes adjacent to a proposed commuter rail line). There may be legal limitations, however, on the ability of funding agencies to acquire land strictly for the purpose of mitigating vibration (or noise) impact.

I c. Evaluate Receiver Treatments — When vibration mitigation treatments cannot be applied at the source or along the propagation path, or if combinations of treatments are required, treatments to the receivers can be considered as described below.
■ Building Modifications — In some circumstances, it is practical to modify the affected building to reduce the vibration level. Vibration isolation of buildings consists of supporting the building foundation on elastomer pads, similar to bridge bearing pads. Vibration isolation of buildings is seldom an option for existing buildings and is typically only possible for new construction. Vibration impacts on sensitive laboratory instruments, such as electron microscopes, may be controlled with vibration isolation tables.

This approach is particularly important for shared -use facilities such as an office space above a transit station or terminal. When vibration - sensitive equipment such as electron microscopes will be affected by transit vibration, specific modifications to the building structure may be the most cost-effective method of controlling the impact aside from modification of equipment mounting systems. For example, the floor upon which the vibration -sensitive equipment is located could be stiffened and isolated from the remainder of the building to reduce the vibration. Alternatively, the equipment mounting systems could be modified or the equipment could be relocated to a different building at far less cost.

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SECTION Noise and Vibration during
7 Construction
Construction noise and vibration often generates complaints from the community, even when construction is for a limited timeframe. Public concerns about construction noise and vibration increase considerably with lengthy periods of heavy construction on major projects as well as prevalence of nighttime construction (often scheduled to avoid disrupting workday road and rail traffic). Noise and vibration complaints typically arise from interference with people's activities, especially when the adjacent community has no clear understanding of the extent or duration of the construction. Misunderstandings can arise when the community thinks a contractor is being insensitive, and the contractor believes it is performing the work in compliance with local ordinances. This situation underscores the need for early identification and assessment of potential problem areas.

This section outlines the procedures for assessing noise and vibration impacts during construction. The type of assessment (qualitative or quantitative) and the level of analysis are determined based on the scale of the project and surrounding land uses. In cases where a full quantitative assessment is not warranted, a qualitative assessment of the construction noise and vibration environment can lead to greater understanding and tolerance in the community.

For major projects with extended periods of construction at specific locations, a quantitative assessment can aid contractors in making bids by allowing changes in construction approach and including mitigation costs before the construction plans are finalized.

Generally, local noise ordinances are not very useful for evaluating construction noise impact. They usually relate to nuisance and hours of allowed activity, and sometimes specify limits in terms of maximum levels, but are generally not practical for assessing the impact of a construction project. Project construction noise criteria should take into account the existing noise environment, the absolute noise levels during construction activities, the duration of the construction, and the adjacent land uses. While it is not the purpose of this manual to specify standardized criteria for construction noise impact, the following guidelines can be considered reasonable criteria for assessment. If these criteria are exceeded, there may be adverse community reaction.

Procedures for assessing construction noise are presented in Section 7. I .

Procedures for assessing construction vibration are presented in Section 7.2.

7. I Construction Noise Assessment
Noise impacts from construction may vary greatly depending on the duration and complexity of the project. The key elements of the Construction Noise Assessment procedure and recommended workflow are as follows.

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Step I: Determine Level of Construction Noise Assessment Step 2: Use a Qualitative Construction Noise Assessment to Estimate Construction Noise
Step 3: Use a Quantitative Construction Noise Assessment to Estimate Construction Noise
Step 4: Assess Construction Noise Impact
Step 5: Determine Construction Noise Mitigation Measures If there is uncertainty in how to determine the appropriate level of assessment, contact the FTA Regional office.

Step I : Determine Level of Construction Noise
Assessment
Determine the appropriate level of assessment based on the scale and type of the project and depending on the stage of environmental review.

Consider the following factors:
■ Scale of the project
■ Proximity of noise -sensitive sites to the construction zones ■ Number of noise -sensitive receivers in the project area ■ Duration of construction activities near noise -sensitive receivers ■ Schedule, including the construction days, hours, and time periods ■ Method (e.g., cut -and -cover vs. bored tunneling)
■ Concern about construction noise expressed in comments by the general public (e.g., through scoping or public meetings) I a. Determine if an assessment is required — Construction Noise Assessments are not required for many small projects including:
■ Installation of safety features like grade -crossing signals; ■ Track improvements within the ROW; or
■ Erecting small buildings and facilities which are similar in scale to the surrounding development.

For small projects like these, include descriptions in the environmental document of the length of construction, the loudest equipment to be used, the expected truck access routes, the avoidance of nighttime activity, and any other relevant planned construction method.

I b. Determine whether a qualitative or quantitative assessment is required
■ Qualitative Construction Noise Assessment — Qualitative Construction Noise Assessments may be required for projects with less than a month of construction time in a noise -sensitive area. See Step 2 for more information on Qualitative Construction Noise Assessments.

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• Quantitative Construction Noise Assessments — Quantitative Construction Noise Assessments may be required for projects with a month or more of construction in noise -sensitive areas or if particularly noisy equipment will be involved. See Step 3 for more information on Quantitative Construction Noise Assessments.

Step 2: Use a Qualitative Construction Noise Assessment to Estimate Construction Noise
Use a qualitative construction noise assessment to estimate construction noise for appropriate projects per Section 7.1, Step I b.

Provide qualitative descriptions in the environmental document of the following elements:
• Duration of construction (both overall and at specific locations) • Equipment expected to be used (e.g., noisiest equipment) • Schedule with limits on times of operation (e.g., daytime use only) • Monitoring of noise
• Forum for communicating with the public
• Commitments to limit noise levels to certain levels, including any local ordinances that apply
• Consideration of application of noise control treatments used successfully in other projects
Effective community outreach and relations are important for these projects.

Disseminate information to the public early regarding the kinds of construction equipment, expected noise levels, and durations to forewarn potentially affected neighbors about the temporary inconvenience. Including a general description of the variation of noise levels during a typical construction day may also be helpful.

Note that the construction criteria in Step 4 do not apply to qualitative assessments.

Step 3: Use a Quantitative Construction Noise Assessment to Estimate Construction Noise
Use a quantitative construction noise assessment to estimate construction noise for appropriate projects per Section 7.1, Step I b.

For Quantitative Construction Noise Assessments, follow the recommended procedure in this step and include a description of the planned construction methods and any basic measures that have been identified to reduce the potential impact, such as prohibiting the noisiest construction activities during the nighttime, in the environmental document. It may be prudent, however, to defer final decisions on noise control measures until the project and construction plans are defined in greater detail during the engineering phase. • Noise Source Levels from Typical Construction Equipment and Operations — The noise levels generated by construction FEDERAL TRANSIT ADMINISTRATION 174

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equipment vary greatly on factors such as the type of equipment, the equipment model, the operation being performed, and the condition of the equipment. Typically, the dominant source of noise from most construction equipment is the engine, often a diesel engine, which usually does not have sufficient muffling. In other cases, such as impact pile -driving or pavement -breaking, noise generated by the process dominates. Construction equipment can be considered to operate in the following two modes for Construction Noise Assessments:
▪ Stationary - Stationary equipment operates in one location for one or more days at a time, with either a fixed power operation (pumps, generators, compressors) or a variable noise operation (pile drivers, pavement breakers).
• Mobile — Mobile equipment moves around the construction site with power applied in cyclic fashion (bulldozers, loaders), or to and from the site (trucks). Movement around the site is considered in the construction noise prediction procedure.

Variation in power imposes additional complexity in characterizing the noise source level from mobile equipment. Describe the noise at a reference distance from the equipment operating at full power and adjusting it based on the duty cycle of the activity to determine the Leg(t) of the operation.

Typical noise levels from representative equipment are included in Table 7-1.

The levels are based on an EPA Report,(61) measured data from railroad construction equipment taken during the 1976 Northeast Corridor Improvement Project, the FHWA Roadway Construction Noise Model, and other measured data.

For equipment that is not represented in Table 7-I, measure the noise levels according to the standard procedures for measuring the exterior noise levels for the certification of mobile and stationary construction equipment by the Society of Automotive Engineers.(62)(63)
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Table 7-I Construction Equipment Noise Emission Levels
Equipment
Typical Noise Level 50 ft
from Source, dBA
Air Compressor
80 Backhoe
80 Ballast Equalizer
82 Ballast Tamper
83 Compactor
82 Concrete Mixer
85 Concrete Pump
82 Concrete Vibrator
76 Crane, Derrick
88 Crane, Mobile
83 Dozer
85 Generator
82 Grader
85 Impact Wrench
85 Jack Hammer
88 Loader
80 Paver
85 Pile-driver (Impact)
101
Pile-driver (Sonic)
95 Pneumatic Tool
85 Pump
77 Rail Saw
90 Rock Drill
95 Roller
85 Saw
76 Scarifier
83 Scraper
85 Shovel
82 Spike Driver
77 Tie Cutter
84 Tie Handler
80 Tie Inserter
85 Truck
84 3a. Use the metric Leq(t) to assess construction noise. This unit is appropriate because Leq(t) can be used to describe:
• Noise level from operation of each piece of equipment separately, and levels can be combined to represent the noise level from all equipment operating during a given period
• Noise level during an entire phase
• Average noise over all phases of the construction
3b. Use Eq. 7- I to predict construction noise impact for major transit projects, considering the noise generated by the equipment and noise propagation due to distance. Calculate Leq.equip for all equipment individually, then use decibel addition to sum the LAeq.equip for all equipment operating during the same time period. See Appendix B. I . I for information on decibel addition.

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Leq.equip - Lemission + 101og(Adjusage) — 20 log(—) — 10G1og(D) Eq. 7-I SO 50
where:

Leq,equip
Lemission
Ad)usage
D
G
= Leq(r)at a receiver from the operation of a single piece of equipment over a specified time period, dBA
= noise emission level of the particular piece of equipment at the reference distance of 50 ft, dBA
= usage factor to account for the fraction of time that the equipment is in use over the specified time period
= distance from the receiver to the piece of equipment, ft = a constant that accounts for topography and ground effects Determine the quantities for Eq. 7- I based on the level of assessment as described below.
• A general assessment of construction noise is warranted for projects in an early assessment stage when the equipment roster and schedule are undefined and only a rough estimate of construction noise levels is practical.
• A detailed analysis of construction noise is warranted when many noise - sensitive sites are adjacent to a construction project or where contractors are faced with stringent local ordinances or heightened public concerns expressed in early outreach efforts.

Complete the appropriate assessment for each phase of construction. Major construction projects are accomplished in several different phases. Each phase has a specific equipment mix, depending on the work to be accomplished during that phase. As a result of the equipment mix, each phase has its own noise characteristics; some phases have higher continuous noise levels than others, and some have higher impact noise levels than others.

Option A: General Assessment — Determine the quantities for Eq. 7- I based on the following assumptions for a General Assessment of each phase of construction.
• Noise emission level (Lemission) — Determine the emission level at 50 ft according to noise from typical construction equipment described above and Table 7-1.
• Usage factor (Adjusage) — Assume a usage factor of I. This assumes a time period of one -hour with full power operation. Most construction equipment operates continuously for periods of one -hour or more during the construction period.

Therefore, 10log(Adjusage/ = 0 and can be omitted from the equation. • Distance (D) — Assume that all equipment operates at the center of the project, or centerline for guideway or highway construction project.

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• Ground effect (G) - G = 0 assuming free -field conditions and ignoring ground effects. If ground effects are of specific importance to the assessment, consider using the Detailed Analysis procedure.

Only determine the Leq.equip for the two noisiest pieces of equipment expected to be used in each phase of construction. Then, sum the levels for each phase of construction using decibel addition.

Option B: Detailed Analysis — Determine the quantities for Eq. 7- I based on the following assumptions for a Detailed Analysis of each phase of construction.

Alternatively, for detailed, long-term, and complex construction projects or projects near a particularly sensitive site, the FHWA's Windows -based screening tool, "Roadway Construction Noise Model (RCNM)," can be used for the prediction of construction noise.(64)
• Noise emission level (Lemission)— Measure or certify the noise emission level for each piece of equipment.
• Usage factor (Adjusaye) — Long-term construction project noise impact is based on a 30 -day average Ld,,, the times of day of construction activity (nighttime noise is penalized by I0 dB in residential areas), and the percentage of time the equipment is used during a period of time that will affect Adjusaye•
For example, an 8 -hour Leq(t) is determined by making Adjusayethe percentage of time each individual piece of equipment operates under full power in that period. Similarly, the 30 -day average Ldr, is determined from the Adjusaye expressed by the percentage of time the equipment is used during the daytime hours (7 a.m. to I0 p.m.) and nighttime (I0 p.m. to 7 a.m.), separately, over a 30 -day period. To account for increased sensitivity to nighttime noise, the nighttime noise levels are adjusted by I 0 dB in the Ldn computation (see Appendix B.I.4.5). • Distance (D) — Determine the location of each piece of equipment during operation and the distance to each receiver.
• Ground effect (G) — Use Table 4-26 in Section 4.5, Step 3 to calculate G to account for the site topography, natural and man-made barriers, and ground effects.

Compute the 8 -hour Leq(t) ( Leq.equip(8hr)) and the 30 -day average Ldn (Ldn.equip(3oday)) for all equipment expected to be used in each phase of construction separately. Then, sum the levels for each phase of construction using Eq. 4-56 and Eq. 4-57 in Table 4-32.

Step 4: Assess Construction Noise Impact
Compare the predicted noise levels from the Quantitative Construction Noise Assessment with impact criteria to assess impact from construction noise for each phase of construction.

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No standardized criteria have been developed for assessing construction noise impact. Consequently, criteria must be developed on a project -specific basis unless local ordinances apply. As stated earlier in this section, local noise ordinances are typically not very useful in evaluating construction noise. They usually relate to nuisance and hours of allowed activity, and sometimes specify limits in terms of maximum levels, but are generally not practical for assessing the impact of a construction project. Project construction noise criteria should account for the existing noise environment, the absolute noise levels during construction activities, the duration of the construction, and the adjacent land use. While it is not the purpose of this manual to specify standardized criteria for construction noise impact, the following guidelines can be considered reasonable criteria for assessment. If these criteria are exceeded, there may be adverse community reaction.

The construction impact guidelines are presented based on the level of quantitative assessment.

Option A: General Assessment — Compare the combined Leq.equip(1hr) for the two noisiest pieces of equipment for each phase of construction determined in Section 7.1, Step 3 to the criteria below. Then, identify locations where the level exceeds the criteria.

Table 7-2 General Assessment Construction Noise Criteria Land Use
Leq.equip(1hr),
Day
dBA
Night
Residential
90 80
Commercial
100
100
Industrial
100
100
Option B: Detailed Analysis — Compare the combined Leq.equip(lhr) and the combined Ldn.equip(3oday) for all equipment for each phase of construction determined in Section 7.1, Step 3 to the criteria below. Then, identify locations where the level exceeds the criteria.

Table 7-3 Detailed Analysis Construction Noise Criteria Land Use
Leq•equip(8hr), dBA
Day Night
Ldn.equip(30day), dBA
30 -day Average
Residential
80 70
75 Commercial
85 85
80*
Industrial
90 90
85*
*Use a 24 -hour Leq(24hr) instead of Ldn.equip(30day).

Step 5: Determine Construction Noise Mitigation
Measures
Evaluate the need for mitigation and select appropriate mitigation measures.

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Where potential impacts have been identified according to Section 7.1, Step 4, evaluate appropriate control measures. Include descriptions of how each affected location will be treated with one or more mitigation measures in the environmental document.
5a. Determine the appropriate approach for construction noise control.

Categories of approaches include:
• Design considerations and project layout
▪ Construct noise barriers, such as temporary walls or piles of excavated material, between noisy activities and noise -sensitive receivers.
▪ Re-route truck traffic away from residential streets. Select streets with the fewest homes if no alternatives are available. ▪ Site equipment on the construction lot as far away from noise - sensitive sites as possible.
▪ Construct walled enclosures around especially noisy activities or clusters of noisy equipment. For example, shields can be used around pavement breakers, and loaded vinyl curtains can be draped under elevated structures.
• Sequence of operations
▪ Combine noisy operations to occur in the same time period. The total noise level produced will not be substantially greater than the level produced if the operations were performed separately. ▪ Avoid nighttime activities. Sensitivity to noise increases during the nighttime hours in residential neighborhoods.
• Alternative construction methods
• Avoid impact pile -driving where possible in noise -sensitive areas.

Drilled piles or the use of a sonic/vibratory pile driver or push pile driver are quieter alternatives where the geological conditions permit their use.
• Use specially -quieted equipment, such as quieted and enclosed air compressors and properly -working mufflers on all engines. • Select quieter demolition methods. For example, sawing bridge decks into sections that can be loaded onto trucks results in lower cumulative noise levels than impact demolition by pavement breakers.

Include descriptions of how each impacted location will be treated with one or more mitigation measures in the environmental impact assessment when possible.
5b. Describe and commit to a mitigation plan that will be developed later when the information is available to make final decisions (not often available during the project development phase) on all specific mitigation measures. This may be the case for large, complex projects. The objective of the plan should be to minimize construction noise using all reasonable (e.g., cost vs. benefit) and feasible (e.g., possible to construct) means available.

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Components of a mitigation plan may include some or all of the following provisions, which should also be specified in construction contracts:
• Equipment noise emission limits — Equipment noise limits are absolute noise limits applied to generic classes of equipment at a reference distance (typically 50 ft). The limits should be set no higher than what is reasonably achievable for well -maintained equipment with effective mufflers. Lower limits that require source noise control may be appropriate for certain equipment when needed to minimize community noise impact, if reasonable and feasible. Provisions could also be included to require equipment noise certification testing prior to use on -site.
• Lot -line construction noise limits — Lot -line construction noise limits are noise limits that apply at the lot -line of specific noise -sensitive properties. The limits are typically specified in terms of both noise exposure (usually Leg(t) over a 20 -30 -minute period) and maximum noise level. They should be based on local noise ordinances if applicable, as well as pre -construction baseline noise levels (usually 3 to 5 dB above the baseline).
• Operational and/or equipment restrictions — It may be necessary to prohibit or restrict certain construction equipment and activities near residential areas during nighttime hours. This is particularly true for activities that generate tonal, impulsive, or repetitive sounds, such as back-up alarms, hoe ram demolition, and pile -driving.
• Noise abatement requirements — In some cases, specifications may be provided for particular noise control treatments based on the results of the design analysis and/or prior commitments made to the public by civic authorities. An example would be the requirement for a temporary noise barrier to shield a particular community area from noisy construction activities.
• Noise monitoring plan requirements — Plans can be developed for pre -project noise monitoring to establish baseline noise levels at sensitive locations, as well as for periodic equipment and lot -line noise monitoring during the construction period. The plan should outline the measurement and reporting methods that will be used to demonstrate compliance with the project noise limits.
• Noise control plan requirements — For major construction projects, preparation and submission of noise control plans on a periodic basis (e.g., every six months) are generally required. These plans should predict the construction noise at noise -sensitive receiver locations based on the proposed construction equipment and methods.

If the analysis predicts that the specified noise limits will be exceeded, the plan should specify the mitigation measures that will be applied and should demonstrate the expected noise reductions these measures will achieve. The objective of this proactive approach is to minimize the FEDERAL TRANSIT ADMINISTRATION 181

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likelihood of community noise complaints by ensuring that any necessary mitigation measures are included in the construction plans. • Compliance enforcement program — If construction noise is an issue in the community, it is important that a program be implemented to monitor contractor compliance with the noise control specifications and mitigation plan. It is recommended that this function be performed by a construction management team on behalf of the public agency. • Public information and complaint response procedures — To maintain positive community relations, it is recommended to keep the public informed about the construction plans and efforts to minimize noise, and procedures should be established for prompt response and corrective action to noise complaints during construction.

Most of these provisions are appropriate for large-scale projects, where construction activity will continue for many months, if not years. The linked references contain more information on construction noise for major transportation projects.(60)(65)

7.2 Construction Vibration Assessment
Construction activity can result in varying degrees of ground vibration, depending on the equipment and methods employed. Operation of construction equipment causes ground vibrations that spread through the ground and diminish in strength with distance. Buildings founded on the soil near the construction site respond to these vibrations with varying results, ranging from no perceptible effects at the lowest levels, low rumbling sounds and perceptible vibrations at moderate levels, and slight damage at the highest levels.

While ground vibrations from construction activities do not often reach the levels that can damage structures, fragile buildings must receive special consideration. The construction vibration criteria include consideration of the building condition.

The key elements of the Construction Vibration Assessment procedures and recommended workflow are as follows:

Step I: Determine level of construction vibration assessment Step 2: Use a qualitative construction vibration assessment Step 3: Use a quantitative construction vibration assessment Step 4: Assess construction vibration impact
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Step I: Determine Level of Construction Vibration
Assessment
Determine the appropriate level of assessment based on the sca/e and type of the project and the stage of environmental review.

I a. Determine if an assessment is required.

Construction Vibration Assessments are not required for many small projects including:
■ Installation of safety features like grade -crossing signals ■ Track improvements within the ROW
■ Erecting small buildings and facilities, which are similar in scale to the surrounding development
I b. Determine whether a qualitative or quantitative assessment is required.
■ Qualitative Construction Vibration Assessment — A qualitative construction vibration assessment is appropriate for projects where prolonged annoyance or damage from construction vibration is not expected. For example, equipment that generates little or no ground vibration —such as air compressors, light trucks, and hydraulic loaders — only require qualitative descriptions. See Section 7.2, Step 2 for more information on qualitative construction vibration assessments. ■ Quantitative Construction Vibration Assessment — A
quantitative construction vibration analysis is appropriate for projects where construction vibration may result in building damage or prolonged annoyance. For example, activities such as blasting, pile - driving, vibratory compaction, demolition, and drilling or excavation near sensitive structures require a quantitative analysis. See Section 7.2, Step 3 for more information on quantitative construction vibration assessments.

If there is uncertainty in how to determine the appropriate level of assessment, contact the FTA Regional office.

Step 2: Use a Qualitative Construction Vibration
Assessment
Use a qualitative construction vibration assessment to estimate vibration for appropriate projects per Section 7.2, Step I b.

Provide qualitative descriptions in the environmental document of the following elements:
■ Duration of construction (both overall and at specific locations) ■ Equipment expected to be used
■ Description of how ground -borne vibration will be maintained at an acceptable level
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Note that the criteria in Section 7.2, Step 4 do not apply to qualitative assessments.

Step 3: Use a Quantitative Construction Vibration
Assessment
Use a quantitative construction vibration assessment to estimate vibration for appropriate projects per Section 7.2, Step 1 b.

For quantitative construction vibration assessments, follow the recommended procedure in this step. Vibration source levels from typical construction equipment and operations are provided below, and procedures on how to estimate construction vibration for damage and annoyance are provided in Steps 3a and 3b, respectively.
• Vibration Source Levels from Construction Equipment — Table 7-4 presents average source levels in terms of velocity for various types of construction equipment measured under a wide variety of construction activities. The approximate rms vibration velocity levels were calculated from the PPV limits using a crest factor of 4, representing a PPV-rms difference of 12 dB. Note that although the table gives one level for each piece of equipment, there is considerable variation in reported ground vibration levels from construction activities. The data in Table 7-4 provide a reasonable estimate for a wide range of soil conditions.(66)(67)(68)(69)
Table 7-4 Vibration Source Levels for Construction Equipment Equipment
PPV at 25
ft, in/sec
Approximate
Lv* at 25 ft
Pile Driver (impact)
upper range

1.518
1 12
typical

0.644
104
Pile Driver (sonic)
upper range

0.734
I05
typical

0.17 93
Clam shovel drop (slurry wall)

0.202
94 Hydromill (slurry
wall)
in soil

0.008
66 in rock

0.017
75 Vibratory Roller

0.21 94
Hoe Ram

0.089
87 Large bulldozer

0.089
87 Caisson drilling

0.089
87 Loaded trucks

0.076
86 Jackhammer

0.035
79 Small bulldozer

0.003
58 RMS velocity in decibels, VdB re I micro-in/sec
3a. Damage Assessment
Assess for building damage for each piece of equipment individually.

Construction vibration is generally assessed in terms of peak particle velocity (PPV), as described in Section S.I.

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• Determine the vibration source level (PPVref) for each piece of equipment at a reference distance of 25 ft as described above and in Table 7-4.
• Use Eq. 7-2 to apply the propagation adjustment to the source reference level to account for the distance from the equipment to the receiver. Note that the equation is based on point sources with normal propagation conditions.
251.5
PPVequip = PPVref x (D )
where:

PPVequip
PPVref
D
Eq. 7-2
= the peak particle velocity of the equipment
adjusted for distance, in/sec
= the source reference vibration level at 25 ft,
in/sec
= distance from the equipment to the receiver, ft
3b. Annoyance Assessment
Assess for annoyance for each piece of equipment individually. Ground -borne vibration related to human annoyance is related to rms velocity levels, expressed in VdB as described in Section 5. I .

Estimate the vibration level (Lv) using Eq. 7-3.

D
Lv.distance = Lvref — 301og(25)
where:

Lv.distance
Lvref
D
= the rms velocity level adjusted for distance, VdB
= the source reference vibration level at 25 ft, VdB
= distance from the equipment to the receiver, ft
Eq. 7-3
Step 4: Assess Construction Vibration Impact
Compare the predicted vibration levels from the Quantitative Construction Vibration Assessment with impact criteria to assess impact from construction vibration.

Assess potential damage effects from construction vibration for each piece of equipment individually. Note that equipment operating at the same time could increase vibration levels substantially, but predicting any increase could be difficult. The criteria presented in this section should be used during the environmental impact assessment phase to identify problem locations that must be addressed during the engineering phase.

Compare the PPV and approximate L,, for each piece of equipment determined in Section 7.2, Step 3 to the vibration damage criteria in Table 7-5, which is presented by building/structural category, to assess impact.(70)(71) The approximate rms vibration velocity levels were calculated from the PPV limits using a crest factor of 4.

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Table 7-5 Construction Vibration Damage Criteria
Building/ Structural Category
PPV, in/sec
Approximate Lv*
I. Reinforced -concrete, steel or timber (no plaster)

0.5 102
II. Engineered concrete and masonry (no plaster)

0.3 98
III. Non -engineered timber and masonry buildings

0.2 94
IV. Buildings extremely susceptible to vibration damage

0.12 90
*RMS velocity in decibels, VdB re I micro-in/sec
Compare the Lv determined in Section 7.2, Step 3 to the criteria for the General Vibration Assessment in Section 6.2 to assess annoyance or interference with vibration -sensitive activities due to construction vibration.

Step 5: Determine Construction Vibration Mitigation
Measures
Evaluate the need for mitigation and select appropriate mitigation measures where potential human impacts or building damage from construction vibration have been identified according to Section 7.2, Step 4.
5a. Determine the appropriate approach for construction vibration mitigation considering equipment location and processes.
• Design considerations and project layout
• Route heavily -loaded trucks away from residential streets. Select streets with the fewest homes if no alternatives are available. ▪ Operate earth -moving equipment on the construction lot as far away from vibration -sensitive sites as possible.
• Sequence of operations
• Phase demolition, earth -moving, and ground -impacting operations so as not to occur in the same time period. Unlike noise, the total vibration level produced could be substantially less when each vibration source operates separately.
▪ Avoid nighttime activities. Sensitivity to vibration increases during the nighttime hours in residential neighborhoods.
• Alternative construction methods
• Carefully consider the use of impact pile -driving versus drilled piles or the use of a sonic/vibratory pile driver or push pile driver where those processes might create lower vibration levels if geological conditions permit their use.
— Pile -driving is one of the greatest sources of vibration associated with equipment used during construction of a project. The source levels in Table 7-4 indicate that sonic pile drivers may provide substantial reduction of vibration levels compared to impact pile drivers. But, there are some additional vibration effects of sonic pile drivers that may limit their use in sensitive locations.
— A sonic pile driver operates by continuously shaking the pile at a fixed frequency, literally vibrating it into the ground. Continuous operation at a fixed frequency may, however, be more
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noticeable to nearby residents, even at lower vibration levels.

Furthermore, the steady-state excitation of the ground may induce a growth in the resonant response of building
components. Resonant response may be unacceptable in cases of fragile buildings or vibration -sensitive manufacturing processes. Impact pile drivers, however, produce a high vibration level for a short time (0.2 seconds) with sufficient time between impacts to allow any resonant response to decay.

Select demolition methods involving little to no impact, where possible. For example, sawing bridge decks into sections that can be loaded onto trucks results in lower vibration levels than impact demolition by pavement breakers. Milling generates lower vibration levels than excavation using clam shell or chisel drops.

Avoid vibratory rollers and packers near sensitive areas. 5b. Describe and commit to a mitigation plan that will be developed and implemented during the engineering and construction phase when the information available during the project development phase will not be sufficient to define specific construction vibration mitigation measures. The objective of the plan should be to minimize construction vibration damage using all reasonable and feasible means available. The plan should include the following components:
■ A procedure for establishing threshold and limiting vibration values for potentially affected structures, based on an assessment of each structure's ability to withstand the loads and displacements due to construction vibrations
■ A commitment to develop a vibration monitoring plan during the engineering phase and to implement a compliance monitoring program during construction
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SECTION Documentation of Noise and
8 Vibration Assessment
The level of required documentation is determined according to the project class of action. Section 2.I covers the appropriate class of action (EIS, EA, or CE) for different projects. If there is uncertainty in the appropriate level of documentation, contact the FTA Regional office.

The noise and vibration analysis must be articulated to the public in a clear, comprehensive manner for all levels of documentation. The technical data and information necessary to withstand scrutiny in the environmental review process must be documented in a way that remains intelligible to the public.

Justification for all assumptions used in the analysis, such as selection of representative measurement sites and all baseline conditions, must be presented for review.

A separate technical report or memorandum is often prepared as a supplement to the environmental document. A technical report is appropriate in cases when including the data from the assessment would create an unreasonably long environmental document. The details of the analysis are important for establishing the basis for the assessment. Therefore, all details in the technical report should be contained in a well -organized format for easy access to the information.

For large-scale projects, the environmental document should contain a summary of the essential analysis information to provide subject matter context and the analysis findings. For these projects, separate technical reports are usually prepared as supplements to the EIS or EA and referred to in the environmental document. For smaller projects, or projects with minimal noise or vibration impact, all of the technical information may be presented in the environmental document itself or in a technical memorandum. Other projects might have no potential for noise or vibration impacts. For those projects, that environmental documentation should explain that no noise or vibration impacts are expected.

This section provides guidance on presenting the necessary noise and vibration information in the environmental document (Section 8. I) and the associated technical report (Section 8.2).

8.I Environmental Document
In the environmental document, provide a summary of the comprehensive noise and vibration information from the technical report and emphasize the salient points of the analysis in a format and style that the public can understand.

Smaller projects may have all of the technical information contained within the environmental document, so take special care in summarizing the technical details to convey the information adequately.

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Step I: Choose the Information to Include
Choose the appropriate noise and vibration analysis information to include based on the level of environmental review and the associated documentation.

I a. Provide full disclosure of noise and vibration impacts in the environmental document, including identification of locations where impacts cannot be mitigated below the severe impact level. In general, an EIS describes significant impacts and plans to mitigate the impacts. For EAs, completion of the environmental review with a finding of no significant impact (FONSI) may depend on mitigation being considered for incorporation in the proposed project. The way mitigation is presented in the environmental document depends on the type of impact (noise or vibration) and the stage of project development and environmental review. Projects that meet the criteria of a CE may also require the completion of a noise and/or vibration analysis, and the results of such an analysis should be documented in a noise memo or the CE documentation.

I b. Document noise impacts — Typically, airborne noise impacts can be accurately predicted during the environmental review. For projects that focus on a single alternative, noise impacts can be accurately identified in the draft environmental document. If mitigation is anticipated, then mitigation options should be explored in the EA or draft EIS; firm decisions on mitigation can be deferred to the final document. But for all projects, decisions on noise mitigation should be made before the final document is approved.

I c. Document vibration impacts — Predicting vibration impacts accurately is more complex because ground -borne vibration may be strongly influenced by subsurface conditions. The geotechnical studies that reveal these conditions are normally undertaken during the engineering phase, after the environmental review process is complete. Therefore, the final environmental document will usually not be able to state with certainty whether mitigation is needed for ground -borne vibration and noise.

If the engineering phase is conducted at the same time as the final environmental document, report the results of the Detailed Vibration Analysis in the final environmental document. If the engineering phase is conducted after the final environmental document, report the results of the General Vibration Assessment in the final environmental document. If impact is determined, include a commitment in the final document to conduct a Detailed Vibration Analysis during the engineering phase to complete the impact assessment. Also, include a discussion on various control measures that could be used and the likelihood that the criteria could be met through the use of one or more of the measures. It may be possible to state a commitment in the final environmental document to adhere to the impact criteria for the Detailed Vibration Analysis, while deferring the selection of specific vibration control measures until the completion of detailed studies in the engineering phase. When work is conducted after FTA signs its final decision document (i.e., ROD, combined FEIS/ROD, or FONSI), additional documentation, such as a reevaluation of the previous decision, may be necessary. FTA recommends contacting the FTA Regional office directly in these situations.

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I d. Describe mitigation measures in the decision document — After the decision document is approved, incorporate the mitigation measures by reference in the actual grant agreements signed by FTA and the project sponsor.

The mitigation measures then become contractual conditions that must be adhered to by the project sponsor.

It is typically appropriate to include the following noise and vibration information in the environmental document, as described in Section 8. I:
• The existing conditions (affected environment)
• The direct impacts from operation (environmental consequences) • The construction impacts (environmental consequences) Step 2: Organize information in the Environmental
Document
Include information in the following sections of the environmental document separating out the noise and vibration information.
2a. Existing Conditions (Affected Environment) — Describe the existing conditions (conditions without the project) in terms of the existing noise and vibration conditions in this section of the document. The primary function of this section is to establish the focus and baseline conditions for the discussion of environmental impacts. Include the following basic information and separate the noise and vibration sections. • Description of noise/vibration metrics, effects and typical levels — Include a targeted summary of relevant information from Section 3 of this manual. This will serve as background for the discussions of noise/vibration levels and characteristics that will follow in later sections. Provide illustrative material to convey typical levels to the public.
• Inventory of noise/vibration-sensitive sites — Describe the approach for identifying noise- and vibration -sensitive sites as well as the identified sites and site descriptions. Use sufficient detail to demonstrate completeness. Document these results on a map.
• Noise/vibration measurements — Document the basis for selecting measurement sites, including tables of sites coordinated with maps showing locations of sites. Summarize the measurement approach and include the justification for the measurement procedures used.

Rancho Mirage City CouncilDecember 18, 2025

Rancho Mirage City Council
December 18, 2025